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<div class="section" id="connections-to-a-database">
<span id="connections"></span><h1>Connections to a database<a class="headerlink" href="#connections-to-a-database" title="Permalink to this headline">¶</a></h1>
<p>A <a class="reference internal" href="#apsw.Connection" title="apsw.Connection"><tt class="xref py py-class docutils literal"><span class="pre">Connection</span></tt></a> encapsulates access to a database. You then use
<a class="reference internal" href="cursor.html#apsw.Cursor" title="apsw.Cursor"><tt class="xref py py-class docutils literal"><span class="pre">cursors</span></tt></a> to issue queries against the database.</p>
<p>You can have multple <a class="reference internal" href="#apsw.Connection" title="apsw.Connection"><tt class="xref py py-class docutils literal"><span class="pre">Connections</span></tt></a> open against
the same database in the same process, across threads and in other
processes.</p>
<div class="section" id="connection-class">
<h2>Connection class<a class="headerlink" href="#connection-class" title="Permalink to this headline">¶</a></h2>
<span class="target" id="index-0"></span><dl class="class">
<dt id="apsw.Connection">
<em class="property">class </em><tt class="descname">Connection</tt><big>(</big><em>filename</em>, <em>flags=SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE</em>, <em>vfs=None</em>, <em>statementcachesize=100</em><big>)</big><a class="headerlink" href="#apsw.Connection" title="Permalink to this definition">¶</a></dt>
<dd><p>This object wraps a <a class="reference external" href="http://www.sqlite.org/c3ref/sqlite3.html">sqlite3 pointer</a>.</p>
<p>Opens the named database. You can use <tt class="docutils literal"><span class="pre">:memory:</span></tt> to get a private temporary
in-memory database that is not shared with any other connections.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
<li><strong>flags</strong> – One or more of the <a class="reference external" href="http://www.sqlite.org/c3ref/c_open_create.html">open flags</a> orred together</li>
<li><strong>vfs</strong> – The name of the <a class="reference external" href="http://www.sqlite.org/c3ref/vfs.html">vfs</a> to use. If <tt class="xref py py-const docutils literal"><span class="pre">None</span></tt> then the default
vfs will be used.</li>
<li><strong>statementcachesize</strong> – Use zero to disable the statement cache,
or a number larger than the total distinct SQL statements you
execute frequently.</li>
</ul>
</td>
</tr>
</tbody>
</table>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="apsw.html#apsw.connection_hooks" title="apsw.connection_hooks"><tt class="xref py py-attr docutils literal"><span class="pre">apsw.connection_hooks</span></tt></a></li>
<li><a class="reference internal" href="execution.html#statementcache"><em>Statement Cache</em></a></li>
<li><a class="reference internal" href="vfs.html#vfs"><em>Virtual File System (VFS)</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/open.html">sqlite3_open_v2</a></p>
</dd></dl>
<dl class="method">
<dt id="apsw.Connection.__enter__">
<tt class="descclassname">Connection.</tt><tt class="descname">__enter__</tt><big>(</big><big>)</big> → context<a class="headerlink" href="#apsw.Connection.__enter__" title="Permalink to this definition">¶</a></dt>
<dd><p>You can use the database as a <a class="reference external" href="http://docs.python.org/reference/datamodel.html#with-statement-context-managers">context manager</a>
as defined in <span class="target" id="index-1"></span><a class="pep reference external" href="http://www.python.org/dev/peps/pep-0343"><strong>PEP 0343</strong></a>. When you use <em>with</em> a transaction is
started. If the block finishes with an exception then the
transaction is rolled back, otherwise it is committed. For example:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="k">with</span> <span class="n">connection</span><span class="p">:</span>
<span class="n">connection</span><span class="o">.</span><span class="n">cursor</span><span class="p">()</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="s">"...."</span><span class="p">)</span>
<span class="k">with</span> <span class="n">connection</span><span class="p">:</span>
<span class="c"># nested is supported</span>
<span class="n">call_function</span><span class="p">(</span><span class="n">connection</span><span class="p">)</span>
<span class="n">connection</span><span class="o">.</span><span class="n">cursor</span><span class="p">()</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="s">"..."</span><span class="p">)</span>
<span class="k">with</span> <span class="n">connection</span> <span class="k">as</span> <span class="n">db</span><span class="p">:</span>
<span class="c"># You can also use 'as'</span>
<span class="n">call_function2</span><span class="p">(</span><span class="n">db</span><span class="p">)</span>
<span class="n">db</span><span class="o">.</span><span class="n">cursor</span><span class="p">()</span><span class="o">.</span><span class="n">execute</span><span class="p">(</span><span class="s">"..."</span><span class="p">)</span>
</pre></div>
</div>
<p>Behind the scenes the <a class="reference external" href="http://www.sqlite.org/lang_savepoint.html">savepoint</a> functionality introduced in
SQLite 3.6.8 is used.</p>
</dd></dl>
<dl class="method">
<dt id="apsw.Connection.__exit__">
<tt class="descclassname">Connection.</tt><tt class="descname">__exit__</tt><big>(</big><big>)</big> → False<a class="headerlink" href="#apsw.Connection.__exit__" title="Permalink to this definition">¶</a></dt>
<dd><p>Implements context manager in conjunction with
<a class="reference internal" href="#apsw.Connection.__enter__" title="apsw.Connection.__enter__"><tt class="xref py py-meth docutils literal"><span class="pre">__enter__()</span></tt></a>. Any exception that happened in the
<em>with</em> block is raised after commiting or rolling back the
savepoint.</p>
</dd></dl>
<span class="target" id="index-2"></span><dl class="method">
<dt id="apsw.Connection.backup">
<tt class="descclassname">Connection.</tt><tt class="descname">backup</tt><big>(</big><em>databasename</em>, <em>sourceconnection</em>, <em>sourcedatabasename</em><big>)</big> → backup<a class="headerlink" href="#apsw.Connection.backup" title="Permalink to this definition">¶</a></dt>
<dd><p>Opens a <a class="reference internal" href="backup.html#backup"><em>backup object</em></a>. All data will be copied from source
database to this database.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>databasename</strong> – Name of the database. This will be <tt class="docutils literal"><span class="pre">main</span></tt> for
the main connection and the name you specified for <a class="reference external" href="http://www.sqlite.org/lang_attach.html">attached</a> databases.</li>
<li><strong>sourceconnection</strong> – The <a class="reference internal" href="#apsw.Connection" title="apsw.Connection"><tt class="xref py py-class docutils literal"><span class="pre">Connection</span></tt></a> to copy a database from.</li>
<li><strong>sourcedatabasename</strong> – Name of the database in the source (eg <tt class="docutils literal"><span class="pre">main</span></tt>).</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last"><a class="reference internal" href="backup.html#apsw.backup" title="apsw.backup"><tt class="xref py py-class docutils literal"><span class="pre">backup</span></tt></a></p>
</td>
</tr>
</tbody>
</table>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="backup.html#backup"><em>Backup</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/backup_finish.html">sqlite3_backup_init</a></p>
</dd></dl>
<span class="target" id="index-3"></span><dl class="method">
<dt id="apsw.Connection.blobopen">
<tt class="descclassname">Connection.</tt><tt class="descname">blobopen</tt><big>(</big><em>database</em>, <em>table</em>, <em>column</em>, <em>rowid</em>, <em>writeable</em><big>)</big> → blob<a class="headerlink" href="#apsw.Connection.blobopen" title="Permalink to this definition">¶</a></dt>
<dd><p>Opens a blob for <a class="reference internal" href="blob.html#blobio"><em>incremental I/O</em></a>.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>database</strong> – <p>Name of the database. This will be <tt class="docutils literal"><span class="pre">main</span></tt> for
the main connection and the name you specified for <a class="reference external" href="http://www.sqlite.org/lang_attach.html">attached</a> databases.</p>
</li>
<li><strong>table</strong> – The name of the table</li>
<li><strong>column</strong> – The name of the column</li>
<li><strong>rowid</strong> – The id that uniquely identifies the row.</li>
<li><strong>writeable</strong> – If True then you can read and write the blob. If False then you can only read it.</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last"><a class="reference internal" href="blob.html#apsw.blob" title="apsw.blob"><tt class="xref py py-class docutils literal"><span class="pre">blob</span></tt></a></p>
</td>
</tr>
</tbody>
</table>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="example.html#example-blobio"><em>Blob I/O example</em></a></li>
<li><a class="reference external" href="http://www.sqlite.org/autoinc.html">SQLite row ids</a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/blob_open.html">sqlite3_blob_open</a></p>
</dd></dl>
<span class="target" id="index-4"></span><dl class="method">
<dt id="apsw.Connection.changes">
<tt class="descclassname">Connection.</tt><tt class="descname">changes</tt><big>(</big><big>)</big> → int<a class="headerlink" href="#apsw.Connection.changes" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the number of database rows that were changed (or inserted
or deleted) by the most recently completed INSERT, UPDATE, or DELETE
statement.</p>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/changes.html">sqlite3_changes</a></p>
</dd></dl>
<span class="target" id="index-5"></span><dl class="method">
<dt id="apsw.Connection.close">
<tt class="descclassname">Connection.</tt><tt class="descname">close</tt><big>(</big><span class="optional">[</span><em>force=False</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#apsw.Connection.close" title="Permalink to this definition">¶</a></dt>
<dd><p>Closes the database. If there are any outstanding <a class="reference internal" href="cursor.html#apsw.Cursor" title="apsw.Cursor"><tt class="xref py py-class docutils literal"><span class="pre">cursors</span></tt></a>, <a class="reference internal" href="blob.html#apsw.blob" title="apsw.blob"><tt class="xref py py-class docutils literal"><span class="pre">blobs</span></tt></a> or <a class="reference internal" href="backup.html#apsw.backup" title="apsw.backup"><tt class="xref py py-class docutils literal"><span class="pre">backups</span></tt></a> then
they are closed too. It is normally not necessary to call this
method as the database is automatically closed when there are no
more references. It is ok to call the method multiple times.</p>
<p>If your user defined functions or collations have direct or indirect
references to the Connection then it won’t be automatically garbage
collected because of circular referencing that can’t be
automatically broken. Calling <em>close</em> will free all those objects
and what they reference.</p>
<p>SQLite is designed to survive power failures at even the most
awkward moments. Consequently it doesn’t matter if it is closed
when the process is exited, or even if the exit is graceful or
abrupt. In the worst case of having a transaction in progress, that
transaction will be rolled back by the next program to open the
database, reverting the database to a know good state.</p>
<p>If <em>force</em> is <em>True</em> then any exceptions are ignored.</p>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/close.html">sqlite3_close</a></p>
</dd></dl>
<span class="target" id="index-6"></span><dl class="method">
<dt id="apsw.Connection.collationneeded">
<tt class="descclassname">Connection.</tt><tt class="descname">collationneeded</tt><big>(</big><em>callable</em><big>)</big><a class="headerlink" href="#apsw.Connection.collationneeded" title="Permalink to this definition">¶</a></dt>
<dd><p><em>callable</em> will be called if a statement requires a <a class="reference external" href="http://en.wikipedia.org/wiki/Collation">collation</a> that hasn’t been
registered. Your callable will be passed two parameters. The first
is the connection object. The second is the name of the
collation. If you have the collation code available then call
<a class="reference internal" href="#apsw.Connection.createcollation" title="apsw.Connection.createcollation"><tt class="xref py py-meth docutils literal"><span class="pre">Connection.createcollation()</span></tt></a>.</p>
<p>This is useful for creating collations on demand. For example you
may include the <a class="reference external" href="http://en.wikipedia.org/wiki/Locale">locale</a> in
the collation name, but since there are thousands of locales in
popular use it would not be useful to <a class="reference internal" href="#apsw.Connection.createcollation" title="apsw.Connection.createcollation"><tt class="xref py py-meth docutils literal"><span class="pre">prereigster</span></tt></a> them all. Using
<a class="reference internal" href="#apsw.Connection.collationneeded" title="apsw.Connection.collationneeded"><tt class="xref py py-meth docutils literal"><span class="pre">collationneeded()</span></tt></a> tells you when you need to
register them.</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="#apsw.Connection.createcollation" title="apsw.Connection.createcollation"><tt class="xref py py-meth docutils literal"><span class="pre">createcollation()</span></tt></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/collation_needed.html">sqlite3_collation_needed</a></p>
</dd></dl>
<span class="target" id="index-7"></span><dl class="method">
<dt id="apsw.Connection.config">
<tt class="descclassname">Connection.</tt><tt class="descname">config</tt><big>(</big><em>op</em><span class="optional">[</span>, <em>*args</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#apsw.Connection.config" title="Permalink to this definition">¶</a></dt>
<dd><table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
<li><strong>op</strong> – A <a class="reference external" href="http://sqlite.org/c3ref/c_dbconfig_enable_fkey.html">configuration operation</a></li>
<li><strong>args</strong> – Zero or more arguments as appropriate for <em>op</em></li>
</ul>
</td>
</tr>
</tbody>
</table>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/db_config.html">sqlite3_db_config</a></p>
</dd></dl>
<span class="target" id="index-8"></span><dl class="method">
<dt id="apsw.Connection.createaggregatefunction">
<tt class="descclassname">Connection.</tt><tt class="descname">createaggregatefunction</tt><big>(</big><em>name</em>, <em>factory</em><span class="optional">[</span>, <em>numargs=-1</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#apsw.Connection.createaggregatefunction" title="Permalink to this definition">¶</a></dt>
<dd><p>Registers an aggregate function. Aggregate functions operate on all
the relevant rows such as counting how many there are.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
<li><strong>name</strong> – The string name of the function. It should be less than 255 characters</li>
<li><strong>callable</strong> – The function that will be called</li>
<li><strong>numargs</strong> – How many arguments the function takes, with -1 meaning any number</li>
</ul>
</td>
</tr>
</tbody>
</table>
<p>When a query starts, the <em>factory</em> will be called and must return a tuple of 3 items:</p>
<blockquote>
<div><dl class="docutils">
<dt>a context object</dt>
<dd>This can be of any type</dd>
<dt>a step function</dt>
<dd>This function is called once for each row. The first parameter
will be the context object and the remaining parameters will be
from the SQL statement. Any value returned will be ignored.</dd>
<dt>a final function</dt>
<dd>This function is called at the very end with the context object
as a parameter. The value returned is set as the return for
the function. The final function is always called even if an
exception was raised by the step function. This allows you to
ensure any resources are cleaned up.</dd>
</dl>
</div></blockquote>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">You can register the same named function but with different
callables and <em>numargs</em>. See
<a class="reference internal" href="#apsw.Connection.createscalarfunction" title="apsw.Connection.createscalarfunction"><tt class="xref py py-meth docutils literal"><span class="pre">createscalarfunction()</span></tt></a> for an example.</p>
</div>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="example.html#aggregate-example"><em>Example</em></a></li>
<li><a class="reference internal" href="#apsw.Connection.createscalarfunction" title="apsw.Connection.createscalarfunction"><tt class="xref py py-meth docutils literal"><span class="pre">createscalarfunction()</span></tt></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/create_function.html">sqlite3_create_function_v2</a></p>
</dd></dl>
<span class="target" id="index-9"></span><dl class="method">
<dt id="apsw.Connection.createcollation">
<tt class="descclassname">Connection.</tt><tt class="descname">createcollation</tt><big>(</big><em>name</em>, <em>callback</em><big>)</big><a class="headerlink" href="#apsw.Connection.createcollation" title="Permalink to this definition">¶</a></dt>
<dd><p>You can control how SQLite sorts (termed <a class="reference external" href="http://en.wikipedia.org/wiki/Collation">collation</a>) when giving the
<tt class="docutils literal"><span class="pre">COLLATE</span></tt> term to a <a class="reference external" href="http://www.sqlite.org/lang_select.html">SELECT</a>. For example your
collation could take into account locale or do numeric sorting.</p>
<p>The <em>callback</em> will be called with two items. It should return -1
if the first is less then the second, 0 if they are equal, and 1 if
first is greater:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">mycollation</span><span class="p">(</span><span class="n">one</span><span class="p">,</span> <span class="n">two</span><span class="p">):</span>
<span class="k">if</span> <span class="n">one</span> <span class="o"><</span> <span class="n">two</span><span class="p">:</span>
<span class="k">return</span> <span class="o">-</span><span class="mi">1</span>
<span class="k">if</span> <span class="n">one</span> <span class="o">==</span> <span class="n">two</span><span class="p">:</span>
<span class="k">return</span> <span class="mi">0</span>
<span class="k">if</span> <span class="n">one</span> <span class="o">></span> <span class="n">two</span><span class="p">:</span>
<span class="k">return</span> <span class="mi">1</span>
</pre></div>
</div>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="example.html#collation-example"><em>Example</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/create_collation.html">sqlite3_create_collation_v2</a></p>
</dd></dl>
<span class="target" id="index-10"></span><dl class="method">
<dt id="apsw.Connection.createmodule">
<tt class="descclassname">Connection.</tt><tt class="descname">createmodule</tt><big>(</big><em>name</em>, <em>datasource</em><big>)</big><a class="headerlink" href="#apsw.Connection.createmodule" title="Permalink to this definition">¶</a></dt>
<dd><p>Registers a virtual table. See <a class="reference internal" href="vtable.html#virtualtables"><em>Virtual Tables</em></a> for details.</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="example.html#example-vtable"><em>Example</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/create_module.html">sqlite3_create_module_v2</a></p>
</dd></dl>
<span class="target" id="index-11"></span><dl class="method">
<dt id="apsw.Connection.createscalarfunction">
<tt class="descclassname">Connection.</tt><tt class="descname">createscalarfunction</tt><big>(</big><em>name</em>, <em>callable</em><span class="optional">[</span>, <em>numargs=-1</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#apsw.Connection.createscalarfunction" title="Permalink to this definition">¶</a></dt>
<dd><p>Registers a scalar function. Scalar functions operate on one set of paramaters once.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
<li><strong>name</strong> – The string name of the function. It should be less than 255 characters</li>
<li><strong>callable</strong> – The function that will be called</li>
<li><strong>numargs</strong> – How many arguments the function takes, with -1 meaning any number</li>
</ul>
</td>
</tr>
</tbody>
</table>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>You can register the same named function but with different
<em>callable</em> and <em>numargs</em>. For example:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="n">connection</span><span class="o">.</span><span class="n">createscalarfunction</span><span class="p">(</span><span class="s">"toip"</span><span class="p">,</span> <span class="n">ipv4convert</span><span class="p">,</span> <span class="mi">4</span><span class="p">)</span>
<span class="n">connection</span><span class="o">.</span><span class="n">createscalarfunction</span><span class="p">(</span><span class="s">"toip"</span><span class="p">,</span> <span class="n">ipv6convert</span><span class="p">,</span> <span class="mi">16</span><span class="p">)</span>
<span class="n">connection</span><span class="o">.</span><span class="n">createscalarfunction</span><span class="p">(</span><span class="s">"toip"</span><span class="p">,</span> <span class="n">strconvert</span><span class="p">,</span> <span class="o">-</span><span class="mi">1</span><span class="p">)</span>
</pre></div>
</div>
<p class="last">The one with the correct <em>numargs</em> will be called and only if that
doesn’t exist then the one with negative <em>numargs</em> will be called.</p>
</div>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="example.html#scalar-example"><em>Example</em></a></li>
<li><a class="reference internal" href="#apsw.Connection.createaggregatefunction" title="apsw.Connection.createaggregatefunction"><tt class="xref py py-meth docutils literal"><span class="pre">createaggregatefunction()</span></tt></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/create_function.html">sqlite3_create_function_v2</a></p>
</dd></dl>
<dl class="method">
<dt id="apsw.Connection.cursor">
<tt class="descclassname">Connection.</tt><tt class="descname">cursor</tt><big>(</big><big>)</big> → Cursor<a class="headerlink" href="#apsw.Connection.cursor" title="Permalink to this definition">¶</a></dt>
<dd><p>Creates a new <a class="reference internal" href="cursor.html#apsw.Cursor" title="apsw.Cursor"><tt class="xref py py-class docutils literal"><span class="pre">Cursor</span></tt></a> object on this database.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><a class="reference internal" href="cursor.html#apsw.Cursor" title="apsw.Cursor"><tt class="xref py py-class docutils literal"><span class="pre">Cursor</span></tt></a></td>
</tr>
</tbody>
</table>
</dd></dl>
<span class="target" id="index-12"></span><dl class="method">
<dt id="apsw.Connection.enableloadextension">
<tt class="descclassname">Connection.</tt><tt class="descname">enableloadextension</tt><big>(</big><em>enable</em><big>)</big><a class="headerlink" href="#apsw.Connection.enableloadextension" title="Permalink to this definition">¶</a></dt>
<dd><p>Enables/disables <a class="reference external" href="http://www.sqlite.org/cvstrac/wiki/wiki?p=LoadableExtensions">extension loading</a>
which is disabled by default.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>enable</strong> – If True then extension loading is enabled, else it is disabled.</td>
</tr>
</tbody>
</table>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="#apsw.Connection.loadextension" title="apsw.Connection.loadextension"><tt class="xref py py-meth docutils literal"><span class="pre">loadextension()</span></tt></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/enable_load_extension.html">sqlite3_enable_load_extension</a></p>
</dd></dl>
<span class="target" id="index-13"></span><dl class="method">
<dt id="apsw.Connection.filecontrol">
<tt class="descclassname">Connection.</tt><tt class="descname">filecontrol</tt><big>(</big><em>dbname</em>, <em>op</em>, <em>pointer</em><big>)</big> → bool<a class="headerlink" href="#apsw.Connection.filecontrol" title="Permalink to this definition">¶</a></dt>
<dd><p>Calls the <a class="reference internal" href="vfs.html#apsw.VFSFile.xFileControl" title="apsw.VFSFile.xFileControl"><tt class="xref py py-meth docutils literal"><span class="pre">xFileControl()</span></tt></a> method on the <a class="reference internal" href="vfs.html#vfs"><em>Virtual File System (VFS)</em></a>
implementing <a class="reference internal" href="vfs.html#apsw.VFSFile" title="apsw.VFSFile"><tt class="xref py py-class docutils literal"><span class="pre">file</span> <span class="pre">access</span></tt></a> for the database.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>dbname</strong> – The name of the database to affect (eg “main”, “temp”, attached name)</li>
<li><strong>op</strong> – A <a class="reference external" href="http://sqlite.org/c3ref/c_fcntl_lockstate.html">numeric code</a> with values less
than 100 reserved for SQLite internal use.</li>
<li><strong>pointer</strong> – A number which is treated as a <tt class="docutils literal"><span class="pre">void</span> <span class="pre">pointer</span></tt> at the C level.</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first last">True or False indicating if the VFS understood the op.</p>
</td>
</tr>
</tbody>
</table>
<p>If you want data returned back then the <em>pointer</em> needs to point to
something mutable. Here is an example using <a class="reference external" href="http://www.python.org/doc/2.5.2/lib/module-ctypes.html">ctypes</a> of
passing a Python dictionary to <a class="reference internal" href="vfs.html#apsw.VFSFile.xFileControl" title="apsw.VFSFile.xFileControl"><tt class="xref py py-meth docutils literal"><span class="pre">xFileControl()</span></tt></a> which
can then modify the dictionary to set return values:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="n">obj</span><span class="o">=</span><span class="p">{</span><span class="s">"foo"</span><span class="p">:</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">:</span> <span class="mi">3</span><span class="p">}</span> <span class="c"># object we want to pass</span>
<span class="n">objwrap</span><span class="o">=</span><span class="n">ctypes</span><span class="o">.</span><span class="n">py_object</span><span class="p">(</span><span class="n">obj</span><span class="p">)</span> <span class="c"># objwrap must live before and after the call else</span>
<span class="c"># it gets garbage collected</span>
<span class="n">connection</span><span class="o">.</span><span class="n">filecontrol</span><span class="p">(</span>
<span class="s">"main"</span><span class="p">,</span> <span class="c"># which db</span>
<span class="mi">123</span><span class="p">,</span> <span class="c"># our op code</span>
<span class="n">ctypes</span><span class="o">.</span><span class="n">addressof</span><span class="p">(</span><span class="n">objwrap</span><span class="p">))</span> <span class="c"># get pointer</span>
</pre></div>
</div>
<p>The <a class="reference internal" href="vfs.html#apsw.VFSFile.xFileControl" title="apsw.VFSFile.xFileControl"><tt class="xref py py-meth docutils literal"><span class="pre">xFileControl()</span></tt></a> method then looks like this:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="k">def</span> <span class="nf">xFileControl</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">op</span><span class="p">,</span> <span class="n">pointer</span><span class="p">):</span>
<span class="k">if</span> <span class="n">op</span><span class="o">==</span><span class="mi">123</span><span class="p">:</span> <span class="c"># our op code</span>
<span class="n">obj</span><span class="o">=</span><span class="n">ctypes</span><span class="o">.</span><span class="n">py_object</span><span class="o">.</span><span class="n">from_address</span><span class="p">(</span><span class="n">pointer</span><span class="p">)</span><span class="o">.</span><span class="n">value</span>
<span class="c"># play with obj - you can use id() to verify it is the same</span>
<span class="k">print</span> <span class="n">obj</span><span class="p">[</span><span class="s">"foo"</span><span class="p">]</span>
<span class="n">obj</span><span class="p">[</span><span class="s">"result"</span><span class="p">]</span><span class="o">=</span><span class="s">"it worked"</span>
<span class="k">return</span> <span class="bp">True</span>
<span class="k">else</span><span class="p">:</span>
<span class="c"># pass to parent/superclass</span>
<span class="k">return</span> <span class="nb">super</span><span class="p">(</span><span class="n">MyFile</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">xFileControl</span><span class="p">(</span><span class="n">op</span><span class="p">,</span> <span class="n">pointer</span><span class="p">)</span>
</pre></div>
</div>
<p>This is how you set the chunk size by which the database grows. Do
not combine it into one line as the c_int would be garbage collected
before the filecontrol call is made:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="n">chunksize</span><span class="o">=</span><span class="n">ctypes</span><span class="o">.</span><span class="n">c_int</span><span class="p">(</span><span class="mi">32768</span><span class="p">)</span>
<span class="n">connection</span><span class="o">.</span><span class="n">filecontrol</span><span class="p">(</span><span class="s">"main"</span><span class="p">,</span> <span class="n">apsw</span><span class="o">.</span><span class="n">SQLITE_FCNTL_CHUNK_SIZE</span><span class="p">,</span> <span class="n">ctypes</span><span class="o">.</span><span class="n">addressof</span><span class="p">(</span><span class="n">chunksize</span><span class="p">))</span>
</pre></div>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/file_control.html">sqlite3_file_control</a></p>
</dd></dl>
<dl class="attribute">
<dt id="apsw.Connection.filename">
<tt class="descclassname">Connection.</tt><tt class="descname">filename</tt><a class="headerlink" href="#apsw.Connection.filename" title="Permalink to this definition">¶</a></dt>
<dd><p>The filename used to open the database.</p>
</dd></dl>
<span class="target" id="index-14"></span><dl class="method">
<dt id="apsw.Connection.getautocommit">
<tt class="descclassname">Connection.</tt><tt class="descname">getautocommit</tt><big>(</big><big>)</big> → bool<a class="headerlink" href="#apsw.Connection.getautocommit" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns if the Connection is in auto commit mode (ie not in a transaction).</p>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/get_autocommit.html">sqlite3_get_autocommit</a></p>
</dd></dl>
<dl class="method">
<dt id="apsw.Connection.getexectrace">
<tt class="descclassname">Connection.</tt><tt class="descname">getexectrace</tt><big>(</big><big>)</big> → callable or None<a class="headerlink" href="#apsw.Connection.getexectrace" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the currently installed (via <a class="reference internal" href="#apsw.Connection.setexectrace" title="apsw.Connection.setexectrace"><tt class="xref py py-meth docutils literal"><span class="pre">setexectrace()</span></tt></a>)
execution tracer.</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="execution.html#tracing"><em>Tracing</em></a></li>
</ul>
</div>
</dd></dl>
<dl class="method">
<dt id="apsw.Connection.getrowtrace">
<tt class="descclassname">Connection.</tt><tt class="descname">getrowtrace</tt><big>(</big><big>)</big> → callable or None<a class="headerlink" href="#apsw.Connection.getrowtrace" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the currently installed (via <a class="reference internal" href="#apsw.Connection.setrowtrace" title="apsw.Connection.setrowtrace"><tt class="xref py py-meth docutils literal"><span class="pre">setrowtrace()</span></tt></a>)
row tracer.</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="execution.html#tracing"><em>Tracing</em></a></li>
</ul>
</div>
</dd></dl>
<span class="target" id="index-15"></span><dl class="method">
<dt id="apsw.Connection.interrupt">
<tt class="descclassname">Connection.</tt><tt class="descname">interrupt</tt><big>(</big><big>)</big><a class="headerlink" href="#apsw.Connection.interrupt" title="Permalink to this definition">¶</a></dt>
<dd><p>Causes any pending operations on the database to abort at the
earliest opportunity. You can call this from any thread. For
example you may have a long running query when the user presses the
stop button in your user interface. <a class="reference internal" href="exceptions.html#apsw.InterruptError" title="apsw.InterruptError"><tt class="xref py py-exc docutils literal"><span class="pre">InterruptError</span></tt></a>
will be raised in the query that got interrupted.</p>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/interrupt.html">sqlite3_interrupt</a></p>
</dd></dl>
<span class="target" id="index-16"></span><dl class="method">
<dt id="apsw.Connection.last_insert_rowid">
<tt class="descclassname">Connection.</tt><tt class="descname">last_insert_rowid</tt><big>(</big><big>)</big> → int<a class="headerlink" href="#apsw.Connection.last_insert_rowid" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the integer key of the most recent insert in the database.</p>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/last_insert_rowid.html">sqlite3_last_insert_rowid</a></p>
</dd></dl>
<span class="target" id="index-17"></span><dl class="method">
<dt id="apsw.Connection.limit">
<tt class="descclassname">Connection.</tt><tt class="descname">limit</tt><big>(</big><em>id</em><span class="optional">[</span>, <em>newval</em><span class="optional">]</span><big>)</big> → int<a class="headerlink" href="#apsw.Connection.limit" title="Permalink to this definition">¶</a></dt>
<dd><p>If called with one parameter then the current limit for that <em>id</em> is
returned. If called with two then the limit is set to <em>newval</em>.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>id</strong> – One of the <a class="reference external" href="http://www.sqlite.org/c3ref/c_limit_attached.html">runtime limit ids</a></li>
<li><strong>newval</strong> – The new limit. This is a 32 bit signed integer even on 64 bit platforms.</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first last">The limit in place on entry to the call.</p>
</td>
</tr>
</tbody>
</table>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="example.html#example-limit"><em>Example</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/limit.html">sqlite3_limit</a></p>
</dd></dl>
<span class="target" id="index-18"></span><dl class="method">
<dt id="apsw.Connection.loadextension">
<tt class="descclassname">Connection.</tt><tt class="descname">loadextension</tt><big>(</big><em>filename</em><span class="optional">[</span>, <em>entrypoint</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#apsw.Connection.loadextension" title="Permalink to this definition">¶</a></dt>
<dd><p>Loads <em>filename</em> as an <a class="reference external" href="http://www.sqlite.org/cvstrac/wiki/wiki?p=LoadableExtensions">extension</a></p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>filename</strong> – The file to load. This must be Unicode or Unicode compatible</li>
<li><strong>entrypoint</strong> – The initialization method to call. If this
parameter is not supplied then the SQLite default of
<tt class="docutils literal"><span class="pre">sqlite3_extension_init</span></tt> is used.</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name" colspan="2">Raises ExtensionLoadingError:</th></tr>
<tr><td> </td><td class="field-body"><p class="first last">If the extension could not be
loaded. The exception string includes more details.</p>
</td>
</tr>
</tbody>
</table>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="#apsw.Connection.enableloadextension" title="apsw.Connection.enableloadextension"><tt class="xref py py-meth docutils literal"><span class="pre">enableloadextension()</span></tt></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/load_extension.html">sqlite3_load_extension</a></p>
</dd></dl>
<dl class="attribute">
<dt id="apsw.Connection.open_flags">
<tt class="descclassname">Connection.</tt><tt class="descname">open_flags</tt><a class="headerlink" href="#apsw.Connection.open_flags" title="Permalink to this definition">¶</a></dt>
<dd><p>The integer flags used to open the database.</p>
</dd></dl>
<dl class="attribute">
<dt id="apsw.Connection.open_vfs">
<tt class="descclassname">Connection.</tt><tt class="descname">open_vfs</tt><a class="headerlink" href="#apsw.Connection.open_vfs" title="Permalink to this definition">¶</a></dt>
<dd><p>The string name of the vfs used to open the database.</p>
</dd></dl>
<span class="target" id="index-19"></span><dl class="method">
<dt id="apsw.Connection.overloadfunction">
<tt class="descclassname">Connection.</tt><tt class="descname">overloadfunction</tt><big>(</big><em>name</em>, <em>nargs</em><big>)</big><a class="headerlink" href="#apsw.Connection.overloadfunction" title="Permalink to this definition">¶</a></dt>
<dd><p>Registers a placeholder function so that a virtual table can provide an implementation via
<a class="reference internal" href="vtable.html#apsw.VTTable.FindFunction" title="apsw.VTTable.FindFunction"><tt class="xref py py-meth docutils literal"><span class="pre">VTTable.FindFunction()</span></tt></a>.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
<li><strong>name</strong> – Function name</li>
<li><strong>nargs</strong> – How many arguments the function takes</li>
</ul>
</td>
</tr>
</tbody>
</table>
<p>Due to <a class="reference external" href="http://www.sqlite.org/cvstrac/tktview?tn=3507">SQLite ticket #3507</a> underlying errors will not be returned.</p>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/overload_function.html">sqlite3_overload_function</a></p>
</dd></dl>
<span class="target" id="index-20"></span><dl class="method">
<dt id="apsw.Connection.setauthorizer">
<tt class="descclassname">Connection.</tt><tt class="descname">setauthorizer</tt><big>(</big><em>callable</em><big>)</big><a class="headerlink" href="#apsw.Connection.setauthorizer" title="Permalink to this definition">¶</a></dt>
<dd><p>While <a class="reference external" href="http://www.sqlite.org/c3ref/prepare.html">preparing</a>
statements, SQLite will call any defined authorizer to see if a
particular action is ok to be part of the statement.</p>
<p>Typical usage would be if you are running user supplied SQL and want
to prevent harmful operations. You should also
set the <a class="reference internal" href="#apsw.Connection" title="apsw.Connection"><tt class="xref py py-class docutils literal"><span class="pre">statementcachesize</span></tt></a> to zero.</p>
<p>The authorizer callback has 5 parameters:</p>
<blockquote>
<div><ul class="simple">
<li>An <a class="reference external" href="http://www.sqlite.org/c3ref/c_alter_table.html">operation code</a></li>
<li>A string (or None) dependent on the operation <a class="reference external" href="http://www.sqlite.org/c3ref/c_alter_table.html">(listed as 3rd)</a></li>
<li>A string (or None) dependent on the operation <a class="reference external" href="http://www.sqlite.org/c3ref/c_alter_table.html">(listed as 4th)</a></li>
<li>A string name of the database (or None)</li>
<li>Name of the innermost trigger or view doing the access (or None)</li>
</ul>
</div></blockquote>
<p>The authorizer callback should return one of <tt class="xref py py-const docutils literal"><span class="pre">SQLITE_OK</span></tt>,
<tt class="xref py py-const docutils literal"><span class="pre">SQLITE_DENY</span></tt> or <tt class="xref py py-const docutils literal"><span class="pre">SQLITE_IGNORE</span></tt>.
(<tt class="xref py py-const docutils literal"><span class="pre">SQLITE_DENY</span></tt> is returned if there is an error in your
Python code).</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="example.html#authorizer-example"><em>Example</em></a></li>
<li><a class="reference internal" href="execution.html#statementcache"><em>Statement Cache</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/set_authorizer.html">sqlite3_set_authorizer</a></p>
</dd></dl>
<span class="target" id="index-21"></span><dl class="method">
<dt id="apsw.Connection.setbusyhandler">
<tt class="descclassname">Connection.</tt><tt class="descname">setbusyhandler</tt><big>(</big><em>callable</em><big>)</big><a class="headerlink" href="#apsw.Connection.setbusyhandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Sets the busy handler to callable. callable will be called with one
integer argument which is the number of prior calls to the busy
callback for the same lock. If the busy callback returns something
that evaluates to False, then SQLite returns <tt class="xref py py-const docutils literal"><span class="pre">SQLITE_BUSY</span></tt> to the
calling code.. If the callback returns something that evaluates to
True, then SQLite tries to open the table again and the cycle
repeats.</p>
<p>If you previously called <a class="reference internal" href="#apsw.Connection.setbusytimeout" title="apsw.Connection.setbusytimeout"><tt class="xref py py-meth docutils literal"><span class="pre">setbusytimeout()</span></tt></a> then
calling this overrides that.</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="#apsw.Connection.setbusytimeout" title="apsw.Connection.setbusytimeout"><tt class="xref py py-meth docutils literal"><span class="pre">Connection.setbusytimeout()</span></tt></a></li>
<li><a class="reference internal" href="tips.html#busyhandling"><em>Busy handling</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/busy_handler.html">sqlite3_busy_handler</a></p>
</dd></dl>
<span class="target" id="index-22"></span><dl class="method">
<dt id="apsw.Connection.setbusytimeout">
<tt class="descclassname">Connection.</tt><tt class="descname">setbusytimeout</tt><big>(</big><em>millseconds</em><big>)</big><a class="headerlink" href="#apsw.Connection.setbusytimeout" title="Permalink to this definition">¶</a></dt>
<dd><p>If the database is locked such as when another connection is making
changes, SQLite will keep retrying. This sets the maximum amount of
time SQLite will keep retrying before giving up. If the database is
still busy then <a class="reference internal" href="exceptions.html#apsw.BusyError" title="apsw.BusyError"><tt class="xref py py-class docutils literal"><span class="pre">apsw.BusyError</span></tt></a> will be returned.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>milliseconds</strong> – Maximum thousandths of a second to wait.</td>
</tr>
</tbody>
</table>
<p>If you previously called <a class="reference internal" href="#apsw.Connection.setbusyhandler" title="apsw.Connection.setbusyhandler"><tt class="xref py py-meth docutils literal"><span class="pre">setbusyhandler()</span></tt></a> then
calling this overrides that.</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="#apsw.Connection.setbusyhandler" title="apsw.Connection.setbusyhandler"><tt class="xref py py-meth docutils literal"><span class="pre">Connection.setbusyhandler()</span></tt></a></li>
<li><a class="reference internal" href="tips.html#busyhandling"><em>Busy handling</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/busy_timeout.html">sqlite3_busy_timeout</a></p>
</dd></dl>
<span class="target" id="index-23"></span><dl class="method">
<dt id="apsw.Connection.setcommithook">
<tt class="descclassname">Connection.</tt><tt class="descname">setcommithook</tt><big>(</big><em>callable</em><big>)</big><a class="headerlink" href="#apsw.Connection.setcommithook" title="Permalink to this definition">¶</a></dt>
<dd><p><em>callable</em> will be called just before a commit. It should return
zero for the commit to go ahead and non-zero for it to be turned
into a rollback. In the case of an exception in your callable, a
non-zero (ie rollback) value is returned.</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="example.html#example-commithook"><em>Example</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/commit_hook.html">sqlite3_commit_hook</a></p>
</dd></dl>
<dl class="method">
<dt id="apsw.Connection.setexectrace">
<tt class="descclassname">Connection.</tt><tt class="descname">setexectrace</tt><big>(</big><em>callable</em><big>)</big><a class="headerlink" href="#apsw.Connection.setexectrace" title="Permalink to this definition">¶</a></dt>
<dd><p><em>callable</em> is called with the cursor, statement and bindings for
each <a class="reference internal" href="cursor.html#apsw.Cursor.execute" title="apsw.Cursor.execute"><tt class="xref py py-meth docutils literal"><span class="pre">execute()</span></tt></a> or <a class="reference internal" href="cursor.html#apsw.Cursor.executemany" title="apsw.Cursor.executemany"><tt class="xref py py-meth docutils literal"><span class="pre">executemany()</span></tt></a> on this
Connection, unless the <a class="reference internal" href="cursor.html#apsw.Cursor" title="apsw.Cursor"><tt class="xref py py-class docutils literal"><span class="pre">Cursor</span></tt></a> installed its own
tracer. Your execution tracer can also abort execution of a
statement.</p>
<p>If <em>callable</em> is <tt class="xref py py-const docutils literal"><span class="pre">None</span></tt> then any existing execution tracer is
removed.</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="execution.html#tracing"><em>Tracing</em></a></li>
<li><a class="reference internal" href="execution.html#rowtracer"><em>Row Tracer</em></a></li>
<li><a class="reference internal" href="cursor.html#apsw.Cursor.setexectrace" title="apsw.Cursor.setexectrace"><tt class="xref py py-meth docutils literal"><span class="pre">Cursor.setexectrace()</span></tt></a></li>
</ul>
</div>
</dd></dl>
<span class="target" id="index-24"></span><dl class="method">
<dt id="apsw.Connection.setprofile">
<tt class="descclassname">Connection.</tt><tt class="descname">setprofile</tt><big>(</big><em>callable</em><big>)</big><a class="headerlink" href="#apsw.Connection.setprofile" title="Permalink to this definition">¶</a></dt>
<dd><p>Sets a callable which is invoked at the end of execution of each
statement and passed the statement string and how long it took to
execute. (The execution time is in nanoseconds.) Note that it is
called only on completion. If for example you do a <tt class="docutils literal"><span class="pre">SELECT</span></tt> and
only read the first result, then you won’t reach the end of the
statement.</p>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/profile.html">sqlite3_profile</a></p>
</dd></dl>
<span class="target" id="index-25"></span><dl class="method">
<dt id="apsw.Connection.setprogresshandler">
<tt class="descclassname">Connection.</tt><tt class="descname">setprogresshandler</tt><big>(</big><em>callable</em><span class="optional">[</span>, <em>nsteps=20</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#apsw.Connection.setprogresshandler" title="Permalink to this definition">¶</a></dt>
<dd><p>Sets a callable which is invoked every <em>nsteps</em> SQLite
inststructions. The callable should return a non-zero value to abort
or zero to continue. (If there is an error in your Python <em>callable</em>
then non-zero will be returned).</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="example.html#example-progress-handler"><em>Example</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/progress_handler.html">sqlite3_progress_handler</a></p>
</dd></dl>
<span class="target" id="index-26"></span><dl class="method">
<dt id="apsw.Connection.setrollbackhook">
<tt class="descclassname">Connection.</tt><tt class="descname">setrollbackhook</tt><big>(</big><em>callable</em><big>)</big><a class="headerlink" href="#apsw.Connection.setrollbackhook" title="Permalink to this definition">¶</a></dt>
<dd><p>Sets a callable which is invoked during a rollback. If <em>callable</em>
is <tt class="xref py py-const docutils literal"><span class="pre">None</span></tt> then any existing rollback hook is removed.</p>
<p>The <em>callable</em> is called with no parameters and the return value is ignored.</p>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/commit_hook.html">sqlite3_rollback_hook</a></p>
</dd></dl>
<dl class="method">
<dt id="apsw.Connection.setrowtrace">
<tt class="descclassname">Connection.</tt><tt class="descname">setrowtrace</tt><big>(</big><em>callable</em><big>)</big><a class="headerlink" href="#apsw.Connection.setrowtrace" title="Permalink to this definition">¶</a></dt>
<dd><p><em>callable</em> is called with the cursor and row being returned for
<a class="reference internal" href="cursor.html#apsw.Cursor" title="apsw.Cursor"><tt class="xref py py-class docutils literal"><span class="pre">cursors</span></tt></a> associated with this Connection, unless
the Cursor installed its own tracer. You can change the data that
is returned or cause the row to be skipped altogether.</p>
<p>If <em>callable</em> is <tt class="xref py py-const docutils literal"><span class="pre">None</span></tt> then any existing row tracer is
removed.</p>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="execution.html#tracing"><em>Tracing</em></a></li>
<li><a class="reference internal" href="execution.html#rowtracer"><em>Row Tracer</em></a></li>
<li><a class="reference internal" href="cursor.html#apsw.Cursor.setexectrace" title="apsw.Cursor.setexectrace"><tt class="xref py py-meth docutils literal"><span class="pre">Cursor.setexectrace()</span></tt></a></li>
</ul>
</div>
</dd></dl>
<span class="target" id="index-27"></span><dl class="method">
<dt id="apsw.Connection.setupdatehook">
<tt class="descclassname">Connection.</tt><tt class="descname">setupdatehook</tt><big>(</big><em>callable</em><big>)</big><a class="headerlink" href="#apsw.Connection.setupdatehook" title="Permalink to this definition">¶</a></dt>
<dd><p>Calls <em>callable</em> whenever a row is updated, deleted or inserted. If
<em>callable</em> is <tt class="xref py py-const docutils literal"><span class="pre">None</span></tt> then any existing update hook is
removed. The update hook cannot make changes to the database while
the query is still executing, but can record them for later use or
apply them in a different connection.</p>
<p>The update hook is called with 4 paramaters:</p>
<blockquote>
<div><dl class="docutils">
<dt>type (int)</dt>
<dd><tt class="xref py py-const docutils literal"><span class="pre">SQLITE_INSERT</span></tt>, <tt class="xref py py-const docutils literal"><span class="pre">SQLITE_DELETE</span></tt> or <tt class="xref py py-const docutils literal"><span class="pre">SQLITE_UPDATE</span></tt></dd>
<dt>database name (string)</dt>
<dd>This is <tt class="docutils literal"><span class="pre">main</span></tt> for the database or the name specified in
<a class="reference external" href="http://sqlite.org/lang_attach.html">ATTACH</a></dd>
<dt>table name (string)</dt>
<dd>The table on which the update happened</dd>
<dt>rowid (64 bit integer)</dt>
<dd>The affected row</dd>
</dl>
</div></blockquote>
<div class="admonition-see-also admonition seealso">
<p class="first admonition-title">See also</p>
<ul class="last simple">
<li><a class="reference internal" href="example.html#example-updatehook"><em>Example</em></a></li>
</ul>
</div>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/update_hook.html">sqlite3_update_hook</a></p>
</dd></dl>
<span class="target" id="index-28"></span><dl class="method">
<dt id="apsw.Connection.setwalhook">
<tt class="descclassname">Connection.</tt><tt class="descname">setwalhook</tt><big>(</big><em>callable</em><big>)</big><a class="headerlink" href="#apsw.Connection.setwalhook" title="Permalink to this definition">¶</a></dt>
<dd><p><em>callable</em> will be called just after data is committed in <a class="reference internal" href="tips.html#wal"><em>Write Ahead Logging</em></a>
mode. It should return <tt class="xref py py-const docutils literal"><span class="pre">SQLITE_OK</span></tt> or an error code. The
callback is called with 3 parameters:</p>
<blockquote>
<div><ul class="simple">
<li>The Connection</li>
<li>The database name (eg “main” or the name of an attached database)</li>
<li>The number of pages in the wal log</li>
</ul>
</div></blockquote>
<p>You can pass in None in order to clear an existing hook.</p>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/wal_hook.html">sqlite3_wal_hook</a></p>
</dd></dl>
<dl class="method">
<dt id="apsw.Connection.sqlite3pointer">
<tt class="descclassname">Connection.</tt><tt class="descname">sqlite3pointer</tt><big>(</big><big>)</big> → int<a class="headerlink" href="#apsw.Connection.sqlite3pointer" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the underlying <a class="reference external" href="http://sqlite.org/c3ref/sqlite3.html">sqlite3 *</a> for the connection. This
method is useful if there are other C level libraries in the same
process and you want them to use the APSW connection handle. The
value is returned as a number using <tt class="xref py py-meth docutils literal"><span class="pre">PyLong_FromVoidPtr()</span></tt> under the
hood. You should also ensure that you increment the reference count on
the <a class="reference internal" href="#apsw.Connection" title="apsw.Connection"><tt class="xref py py-class docutils literal"><span class="pre">Connection</span></tt></a> for as long as the other libraries are using
the pointer. It is also a very good idea to call
<a class="reference internal" href="apsw.html#apsw.sqlitelibversion" title="apsw.sqlitelibversion"><tt class="xref py py-meth docutils literal"><span class="pre">sqlitelibversion()</span></tt></a> and ensure it is the same as the other
libraries.</p>
</dd></dl>
<span class="target" id="index-29"></span><dl class="method">
<dt id="apsw.Connection.totalchanges">
<tt class="descclassname">Connection.</tt><tt class="descname">totalchanges</tt><big>(</big><big>)</big> → int<a class="headerlink" href="#apsw.Connection.totalchanges" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the total number of database rows that have be modified,
inserted, or deleted since the database connection was opened.</p>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/total_changes.html">sqlite3_total_changes</a></p>
</dd></dl>
<span class="target" id="index-30"></span><dl class="method">
<dt id="apsw.Connection.wal_autocheckpoint">
<tt class="descclassname">Connection.</tt><tt class="descname">wal_autocheckpoint</tt><big>(</big><em>n</em><big>)</big><a class="headerlink" href="#apsw.Connection.wal_autocheckpoint" title="Permalink to this definition">¶</a></dt>
<dd><p>Sets how often the <a class="reference internal" href="tips.html#wal"><em>Write Ahead Logging</em></a> checkpointing is run.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>n</strong> – A number representing the checkpointing interval or
zero/negative to disable auto checkpointing.</td>
</tr>
</tbody>
</table>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/wal_autocheckpoint.html">sqlite3_wal_autocheckpoint</a></p>
</dd></dl>
<span class="target" id="index-31"></span><dl class="method">
<dt id="apsw.Connection.wal_checkpoint">
<tt class="descclassname">Connection.</tt><tt class="descname">wal_checkpoint</tt><big>(</big><em>dbname=None</em>, <em>mode=apsw.SQLITE_CHECKPOINT_PASSIVE) -> ( int</em>, <em>int</em><big>)</big><a class="headerlink" href="#apsw.Connection.wal_checkpoint" title="Permalink to this definition">¶</a></dt>
<dd><p>Does a WAL checkpoint. Has no effect if the database(s) are not in WAL mode.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
<li><strong>dbname</strong> – The name of the database or all databases if None</li>
<li><strong>mode</strong> – One of the <a class="reference external" href="http://sqlite.org/c3ref/wal_checkpoint_v2.html">checkpoint modes</a>.</li>
</ul>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first last">A tuple of the size of the WAL log in frames and the
number of frames checkpointed as described in the
<a class="reference external" href="http://sqlite.org/c3ref/wal_checkpoint_v2.html">documentation</a>.</p>
</td>
</tr>
</tbody>
</table>
<p>Calls: <a class="reference external" href="http://www.sqlite.org/c3ref/wal_checkpoint_v2.html">sqlite3_wal_checkpoint_v2</a></p>
</dd></dl>
</div>
</div>
</div>
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<li><a class="reference internal" href="#">Connections to a database</a><ul>
<li><a class="reference internal" href="#connection-class">Connection class</a></li>
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© <a href="copyright.html">Copyright</a> 2004-2010, Roger Binns <rogerb@rogerbinns.com>.
Last updated on May 20, 2011.
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