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<div class="sect1" lang="en">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="migration-executing-commands"></a>Executing commands</h2></div></div></div>
<div class="sect2" lang="en">
<div class="titlepage"><div><div><h3 class="title">
<a name="migration-creating-commands"></a>Creating commands</h3></div></div></div>
<p>
It can be made, more or less, as in the old version, using
<a class="link" href="libgda-gda-command.html#gda-command-new" title="gda_command_new ()">gda_command_new()</a>, but
now, this function needs a few parameters and, in this version,
you do not link a command to a connection, so you execute a
command in a connection as we'll see <a class="link" href="migration-executing-commands.html#migration-executing-non-queries" title="Executing non queries">later</a>. You
can see how to create commands and examples about this <a class="link" href="processing-queries.html#building-commands" title="Building commands">here</a>.
</p>
</div>
<div class="sect2" lang="en">
<div class="titlepage"><div><div><h3 class="title">
<a name="migration-executing-non-queries"></a>Executing <span class="emphasis"><em>non queries</em></span>
</h3></div></div></div>
<p>
<span class="emphasis"><em>Non queries</em></span> are queries that do not return
data, as insertions, deletions, and so on. The function we use is
<a class="link" href="libgda-GdaConnection.html#gda-connection-execute-non-query" title="gda_connection_execute_non_query ()">gda_connection_execute_non_query
()</a> and returns the number of affected tuples or -1 in case
of error. <a class="link" href="processing-queries.html#making-queries" title="Making non queries">Here</a> you see an
example.
</p>
<p>
It is better not to execute more than one <a href="http://foldoc.doc.ic.ac.uk/foldoc/foldoc.cgi?query=SQL"><span class="acronym">SQL</span></a> sentence for each
command because the result can be unexpected.
</p>
</div>
<div class="sect2" lang="en">
<div class="titlepage"><div><div><h3 class="title">
<a name="migration-executing-normal-queries"></a>Executing normal queries</h3></div></div></div>
<p>
A normal query is a query that return data. This is made as a
<a class="link" href="libgda-GdaDataModel.html" title="GdaDataModel">data model</a>, analogous
to <span class="emphasis"><em>GdaRecordset</em></span> in the old
version<sup>[<a name="id448341" href="#ftn.id448341" class="footnote">5</a>]</sup>.
</p>
<p>
As you can see in the following example, the function we use to
obtain data from a <a href="http://foldoc.doc.ic.ac.uk/foldoc/foldoc.cgi?query=SQL"><span class="acronym">SQL</span></a> sentence is <a class="link" href="libgda-GdaConnection.html#gda-connection-execute-single-command" title="gda_connection_execute_single_command ()">gda_connection_execute_single_command
()</a> and needs the parameters of <a class="link" href="migration-executing-commands.html#migration-executing-non-queries" title="Executing non queries">non queries</a>. The
difference is that now the function returns the <a class="link" href="libgda-GdaDataModel.html" title="GdaDataModel">data model</a> or
<span class="emphasis"><em>NULL</em></span> in case of error.
</p>
<p>
As in the case of <a class="link" href="libgda-GdaConnection.html#gda-connection-execute-non-query" title="gda_connection_execute_non_query ()">non queries</a>, you
must not use several semicolon-separated sentences, because you
have a special function to do this<sup>[<a name="id448387" href="#ftn.id448387" class="footnote">6</a>]</sup>, but it is not recommended.
</p>
</div>
<div class="footnotes">
<br><hr width="100" align="left">
<div class="footnote"><p><sup>[<a name="ftn.id448341" href="#id448341" class="para">5</a>] </sup>Now you have a <a class="link" href="libgda-provider-recordset.html" title="The recordset class">GdaRecordset</a> class,
but it is not recommended.</p></div>
<div class="footnote"><p><sup>[<a name="ftn.id448387" href="#id448387" class="para">6</a>] </sup><a class="link" href="libgda-GdaConnection.html#gda-connection-execute-command" title="gda_connection_execute_command ()">gda_connection_execute_command
()</a></p></div>
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