php-doc-en/reference/pgsql/functions/pg-query.xml

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<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<!-- splitted from ./en/functions/pgsql.xml, last change in rev 1.2 -->
<refentry xml:id="function.pg-query" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>pg_query</refname>
<refpurpose>Execute a query</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type class="union"><type>PgSql\Result</type><type>false</type></type><methodname>pg_query</methodname>
<methodparam choice="opt"><type>PgSql\Connection</type><parameter>connection</parameter></methodparam>
<methodparam><type>string</type><parameter>query</parameter></methodparam>
</methodsynopsis>
<para>
<function>pg_query</function> executes the <parameter>query</parameter>
on the specified database <parameter>connection</parameter>.
<function>pg_query_params</function> should be preferred
in most cases.
</para>
<para>
If an error occurs, and &false; is returned, details of the error can
be retrieved using the <function>pg_last_error</function>
function if the connection is valid.
</para>
<para>
<note>
<simpara>
Although <parameter>connection</parameter> can be omitted, it
is not recommended, since it can be the cause of hard to find
bugs in scripts.
</simpara>
</note>
</para>
<note>
<para>
This function used to be called <function>pg_exec</function>.
<function>pg_exec</function> is still available for compatibility
reasons, but users are encouraged to use the newer name.
</para>
</note>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term><parameter>connection</parameter></term>
<listitem>
&pgsql.parameter.connection-with-unspecified-default;
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>query</parameter></term>
<listitem>
<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.
</para>
<warning>
<para>
String interpolation of user-supplied data is extremely dangerous and is
likely to lead to <link linkend="security.database.sql-injection">SQL
injection</link> vulnerabilities. In most cases
<function>pg_query_params</function> should be preferred, passing
user-supplied values as parameters rather than substituting them into
the query string.
</para>
<para>
Any user-supplied data substituted directly into a query string should
be <link linkend="function.pg-escape-string">properly escaped</link>.
</para>
</warning>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
An <classname>PgSql\Result</classname> instance on success, &return.falseforfailure;.
</para>
</refsect1>
<refsect1 role="changelog">
&reftitle.changelog;
<informaltable>
<tgroup cols="2">
<thead>
<row>
<entry>&Version;</entry>
<entry>&Description;</entry>
</row>
</thead>
<tbody>
&pgsql.changelog.return-result-object;
&pgsql.changelog.connection-object;
</tbody>
</tgroup>
</informaltable>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title><function>pg_query</function> example</title>
<programlisting role="php">
<![CDATA[
<?php
$conn = pg_pconnect("dbname=publisher");
if (!$conn) {
echo "An error occurred.\n";
exit;
}
$result = pg_query($conn, "SELECT author, email FROM authors");
if (!$result) {
echo "An error occurred.\n";
exit;
}
while ($row = pg_fetch_row($result)) {
echo "Author: $row[0] E-mail: $row[1]";
echo "<br />\n";
}
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Using <function>pg_query</function> with multiple statements</title>
<programlisting role="php">
<![CDATA[
<?php
$conn = pg_pconnect("dbname=publisher");
// these statements will be executed as one transaction
$query = "UPDATE authors SET author=UPPER(author) WHERE id=1;";
$query .= "UPDATE authors SET author=LOWER(author) WHERE id=2;";
$query .= "UPDATE authors SET author=NULL WHERE id=3;";
pg_query($conn, $query);
?>
]]>
</programlisting>
</example>
</para>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>pg_connect</function></member>
<member><function>pg_pconnect</function></member>
<member><function>pg_fetch_array</function></member>
<member><function>pg_fetch_object</function></member>
<member><function>pg_num_rows</function></member>
<member><function>pg_affected_rows</function></member>
</simplelist>
</para>
</refsect1>
</refentry>
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