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<h1 class="refname">pg_query</h1>
<p class="verinfo">(PHP 4 >= 4.2.0, PHP 5)</p><p class="refpurpose"><span class="refname">pg_query</span> — <span class="dc-title">Execute a query</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.pg-query-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">resource</span> <span class="methodname"><strong>pg_query</strong></span>
([ <span class="methodparam"><span class="type">resource</span> <code class="parameter">$connection</code></span>
], <span class="methodparam"><span class="type">string</span> <code class="parameter">$query</code></span>
)</div>
<p class="para rdfs-comment">
<span class="function"><strong>pg_query()</strong></span> executes the <em><code class="parameter">query</code></em>
on the specified database <em><code class="parameter">connection</code></em>.
<span class="function"><a href="function.pg-query-params.html" class="function">pg_query_params()</a></span> should be preferred
in most cases.
</p>
<p class="para">
If an error occurs, and <strong><code>FALSE</code></strong> is returned, details of the error can
be retrieved using the <span class="function"><a href="function.pg-last-error.html" class="function">pg_last_error()</a></span>
function if the connection is valid.
</p>
<p class="para">
<blockquote class="note"><p><strong class="note">Note</strong>:
<span class="simpara">
Although <em><code class="parameter">connection</code></em> can be omitted, it
is not recommended, since it can be the cause of hard to find
bugs in scripts.
</span>
</p></blockquote>
</p>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
This function used to be called <span class="function"><strong>pg_exec()</strong></span>.
<span class="function"><strong>pg_exec()</strong></span> is still available for compatibility
reasons, but users are encouraged to use the newer name.
</p>
</p></blockquote>
</div>
<div class="refsect1 parameters" id="refsect1-function.pg-query-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">connection</code></em></span>
<dd>
<p class="para">
PostgreSQL database connection resource. When
<em><code class="parameter">connection</code></em> is not present, the default connection
is used. The default connection is the last connection made by
<span class="function"><a href="function.pg-connect.html" class="function">pg_connect()</a></span> or <span class="function"><a href="function.pg-pconnect.html" class="function">pg_pconnect()</a></span>.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">query</code></em></span>
<dd>
<p class="para">
The SQL statement or statements to be executed. When multiple statements are passed to the function,
they are automatically executed as one transaction, unless there are explicit BEGIN/COMMIT commands
included in the query string. However, using multiple transactions in one function call is not recommended.
</p>
<div class="warning"><strong class="warning">Warning</strong>
<p class="para">
String interpolation of user-supplied data is extremely dangerous and is
likely to lead to <a href="security.database.sql-injection.html" class="link">SQL
injection</a> vulnerabilities. In most cases
<span class="function"><a href="function.pg-query-params.html" class="function">pg_query_params()</a></span> should be preferred, passing
user-supplied values as parameters rather than substituting them into
the query string.
</p>
<p class="para">
Any user-supplied data substituted directly into a query string should
be <a href="function.pg-escape-string.html" class="link">properly escaped</a>.
</p>
</div>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.pg-query-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
A query result resource on success or <strong><code>FALSE</code></strong> on failure.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.pg-query-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-2110">
<p><strong>Example #1 <span class="function"><strong>pg_query()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br />$conn </span><span style="color: #007700">= </span><span style="color: #0000BB">pg_pconnect</span><span style="color: #007700">(</span><span style="color: #DD0000">"dbname=publisher"</span><span style="color: #007700">);<br />if (!</span><span style="color: #0000BB">$conn</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"An error occurred.\n"</span><span style="color: #007700">;<br /> exit;<br />}<br /><br /></span><span style="color: #0000BB">$result </span><span style="color: #007700">= </span><span style="color: #0000BB">pg_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$conn</span><span style="color: #007700">, </span><span style="color: #DD0000">"SELECT author, email FROM authors"</span><span style="color: #007700">);<br />if (!</span><span style="color: #0000BB">$result</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"An error occurred.\n"</span><span style="color: #007700">;<br /> exit;<br />}<br /><br />while (</span><span style="color: #0000BB">$row </span><span style="color: #007700">= </span><span style="color: #0000BB">pg_fetch_row</span><span style="color: #007700">(</span><span style="color: #0000BB">$result</span><span style="color: #007700">)) {<br /> echo </span><span style="color: #DD0000">"Author: </span><span style="color: #0000BB">$row</span><span style="color: #007700">[</span><span style="color: #0000BB">0</span><span style="color: #007700">]</span><span style="color: #DD0000"> E-mail: </span><span style="color: #0000BB">$row</span><span style="color: #007700">[</span><span style="color: #0000BB">1</span><span style="color: #007700">]</span><span style="color: #DD0000">"</span><span style="color: #007700">;<br /> echo </span><span style="color: #DD0000">"<br />\n"</span><span style="color: #007700">;<br />}<br /> <br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
<p class="para">
<div class="example" id="example-2111">
<p><strong>Example #2 Using <span class="function"><strong>pg_query()</strong></span> with multiple statements</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br />$conn </span><span style="color: #007700">= </span><span style="color: #0000BB">pg_pconnect</span><span style="color: #007700">(</span><span style="color: #DD0000">"dbname=publisher"</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// these statements will be executed as one transaction<br /><br /></span><span style="color: #0000BB">$query </span><span style="color: #007700">= </span><span style="color: #DD0000">"UPDATE authors SET author=UPPER(author) WHERE id=1;"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$query </span><span style="color: #007700">.= </span><span style="color: #DD0000">"UPDATE authors SET author=LOWER(author) WHERE id=2;"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$query </span><span style="color: #007700">.= </span><span style="color: #DD0000">"UPDATE authors SET author=NULL WHERE id=3;"</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">pg_query</span><span style="color: #007700">(</span><span style="color: #0000BB">$conn</span><span style="color: #007700">, </span><span style="color: #0000BB">$query</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.pg-query-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.pg-connect.html" class="function" rel="rdfs-seeAlso">pg_connect()</a> - Open a PostgreSQL connection</span></li>
<li class="member"> <span class="function"><a href="function.pg-pconnect.html" class="function" rel="rdfs-seeAlso">pg_pconnect()</a> - Open a persistent PostgreSQL connection</span></li>
<li class="member"> <span class="function"><a href="function.pg-fetch-array.html" class="function" rel="rdfs-seeAlso">pg_fetch_array()</a> - Fetch a row as an array</span></li>
<li class="member"> <span class="function"><a href="function.pg-fetch-object.html" class="function" rel="rdfs-seeAlso">pg_fetch_object()</a> - Fetch a row as an object</span></li>
<li class="member"> <span class="function"><a href="function.pg-num-rows.html" class="function" rel="rdfs-seeAlso">pg_num_rows()</a> - Returns the number of rows in a result</span></li>
<li class="member"> <span class="function"><a href="function.pg-affected-rows.html" class="function" rel="rdfs-seeAlso">pg_affected_rows()</a> - Returns number of affected records (tuples)</span></li>
</ul>
</p>
</div>
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