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<h1 class="refname">PDOStatement::bindParam</h1>
<p class="verinfo">(PHP 5 >= 5.1.0, PECL pdo >= 0.1.0)</p><p class="refpurpose"><span class="refname">PDOStatement::bindParam</span> — <span class="dc-title">
Binds a parameter to the specified variable name
</span></p>
</div>
<div class="refsect1 description" id="refsect1-pdostatement.bindparam-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span> <span class="type">bool</span> <span class="methodname"><strong>PDOStatement::bindParam</strong></span>
( <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$parameter</code></span>
, <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter reference">&$variable</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$data_type</code><span class="initializer"> = PDO::PARAM_STR</span></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$length</code></span>
[, <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$driver_options</code></span>
]]] )</div>
<p class="para rdfs-comment">
Binds a PHP variable to a corresponding named or question mark placeholder
in the SQL statement that was used to prepare the statement. Unlike
<span class="function"><a href="pdostatement.bindvalue.html" class="function">PDOStatement::bindValue()</a></span>, the variable is bound as a
reference and will only be evaluated at the time that
<span class="function"><a href="pdostatement.execute.html" class="function">PDOStatement::execute()</a></span> is called.
</p>
<p class="para">
Most parameters are input parameters, that is, parameters that are used
in a read-only fashion to build up the query. Some drivers support the
invocation of stored procedures that return data as output parameters,
and some also as input/output parameters that both send in data and are
updated to receive it.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-pdostatement.bindparam-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">parameter</code></em></span>
<dd>
<p class="para">
Parameter identifier. For a prepared statement using named
placeholders, this will be a parameter name of the form
<var class="varname"><var class="varname">:name</var></var>. For a prepared statement using
question mark placeholders, this will be the 1-indexed position of
the parameter.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">variable</code></em></span>
<dd>
<p class="para">
Name of the PHP variable to bind to the SQL statement parameter.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">data_type</code></em></span>
<dd>
<p class="para">
Explicit data type for the parameter using the <a href="pdo.constants.html" class="link"><em>PDO::PARAM_*</em>
constants</a>.
To return an INOUT parameter from a stored procedure,
use the bitwise OR operator to set the PDO::PARAM_INPUT_OUTPUT bits
for the <em><code class="parameter">data_type</code></em> parameter.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">length</code></em></span>
<dd>
<p class="para">
Length of the data type. To indicate that a parameter is an OUT
parameter from a stored procedure, you must explicitly set the
length.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">driver_options</code></em></span>
<dd>
<p class="para">
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-pdostatement.bindparam-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure.
</p>
</div>
<div class="refsect1 examples" id="refsect1-pdostatement.bindparam-examples">
<h3 class="title">Examples</h3>
<div class="example" id="example-934"><p><strong>Example #1 Execute a prepared statement with named placeholders</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">/* Execute a prepared statement by binding PHP variables */<br /></span><span style="color: #0000BB">$calories </span><span style="color: #007700">= </span><span style="color: #0000BB">150</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$colour </span><span style="color: #007700">= </span><span style="color: #DD0000">'red'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$sth </span><span style="color: #007700">= </span><span style="color: #0000BB">$dbh</span><span style="color: #007700">-></span><span style="color: #0000BB">prepare</span><span style="color: #007700">(</span><span style="color: #DD0000">'SELECT name, colour, calories<br /> FROM fruit<br /> WHERE calories < :calories AND colour = :colour'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$sth</span><span style="color: #007700">-></span><span style="color: #0000BB">bindParam</span><span style="color: #007700">(</span><span style="color: #DD0000">':calories'</span><span style="color: #007700">, </span><span style="color: #0000BB">$calories</span><span style="color: #007700">, </span><span style="color: #0000BB">PDO</span><span style="color: #007700">::</span><span style="color: #0000BB">PARAM_INT</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$sth</span><span style="color: #007700">-></span><span style="color: #0000BB">bindParam</span><span style="color: #007700">(</span><span style="color: #DD0000">':colour'</span><span style="color: #007700">, </span><span style="color: #0000BB">$colour</span><span style="color: #007700">, </span><span style="color: #0000BB">PDO</span><span style="color: #007700">::</span><span style="color: #0000BB">PARAM_STR</span><span style="color: #007700">, </span><span style="color: #0000BB">12</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$sth</span><span style="color: #007700">-></span><span style="color: #0000BB">execute</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
<div class="example" id="example-935"><p><strong>Example #2 Execute a prepared statement with question mark placeholders</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">/* Execute a prepared statement by binding PHP variables */<br /></span><span style="color: #0000BB">$calories </span><span style="color: #007700">= </span><span style="color: #0000BB">150</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$colour </span><span style="color: #007700">= </span><span style="color: #DD0000">'red'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$sth </span><span style="color: #007700">= </span><span style="color: #0000BB">$dbh</span><span style="color: #007700">-></span><span style="color: #0000BB">prepare</span><span style="color: #007700">(</span><span style="color: #DD0000">'SELECT name, colour, calories<br /> FROM fruit<br /> WHERE calories < ? AND colour = ?'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$sth</span><span style="color: #007700">-></span><span style="color: #0000BB">bindParam</span><span style="color: #007700">(</span><span style="color: #0000BB">1</span><span style="color: #007700">, </span><span style="color: #0000BB">$calories</span><span style="color: #007700">, </span><span style="color: #0000BB">PDO</span><span style="color: #007700">::</span><span style="color: #0000BB">PARAM_INT</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$sth</span><span style="color: #007700">-></span><span style="color: #0000BB">bindParam</span><span style="color: #007700">(</span><span style="color: #0000BB">2</span><span style="color: #007700">, </span><span style="color: #0000BB">$colour</span><span style="color: #007700">, </span><span style="color: #0000BB">PDO</span><span style="color: #007700">::</span><span style="color: #0000BB">PARAM_STR</span><span style="color: #007700">, </span><span style="color: #0000BB">12</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$sth</span><span style="color: #007700">-></span><span style="color: #0000BB">execute</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
<div class="example" id="example-936"><p><strong>Example #3 Call a stored procedure with an INOUT parameter</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">/* Call a stored procedure with an INOUT parameter */<br /></span><span style="color: #0000BB">$colour </span><span style="color: #007700">= </span><span style="color: #DD0000">'red'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$sth </span><span style="color: #007700">= </span><span style="color: #0000BB">$dbh</span><span style="color: #007700">-></span><span style="color: #0000BB">prepare</span><span style="color: #007700">(</span><span style="color: #DD0000">'CALL puree_fruit(?)'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$sth</span><span style="color: #007700">-></span><span style="color: #0000BB">bindParam</span><span style="color: #007700">(</span><span style="color: #0000BB">1</span><span style="color: #007700">, </span><span style="color: #0000BB">$colour</span><span style="color: #007700">, </span><span style="color: #0000BB">PDO</span><span style="color: #007700">::</span><span style="color: #0000BB">PARAM_STR</span><span style="color: #007700">|</span><span style="color: #0000BB">PDO</span><span style="color: #007700">::</span><span style="color: #0000BB">PARAM_INPUT_OUTPUT</span><span style="color: #007700">, </span><span style="color: #0000BB">12</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$sth</span><span style="color: #007700">-></span><span style="color: #0000BB">execute</span><span style="color: #007700">();<br />print(</span><span style="color: #DD0000">"After pureeing fruit, the colour is: </span><span style="color: #0000BB">$colour</span><span style="color: #DD0000">"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</div>
<div class="refsect1 seealso" id="refsect1-pdostatement.bindparam-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="pdo.prepare.html" class="function" rel="rdfs-seeAlso">PDO::prepare()</a> - Prepares a statement for execution and returns a statement object</span></li>
<li class="member"> <span class="function"><a href="pdostatement.execute.html" class="function" rel="rdfs-seeAlso">PDOStatement::execute()</a> - Executes a prepared statement</span></li>
<li class="member"> <span class="function"><a href="pdostatement.bindvalue.html" class="function" rel="rdfs-seeAlso">PDOStatement::bindValue()</a> - Binds a value to a parameter</span></li>
</ul>
</p>
</div>
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