📄 pdostatement.closecursor.html
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> <head> <title>Closes the cursor, enabling the statement to be executed again.</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="pdostatement.bindvalue.html">PDOStatement->bindValue</a></div> <div class="next" style="text-align: right; float: right;"><a href="pdostatement.columncount.html">PDOStatement->columnCount</a></div> <div class="up"><a href="class.pdostatement.html">PDOStatement</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="pdostatement.closecursor" class="refentry"> <div class="refnamediv"> <h1 class="refname">PDOStatement->closeCursor</h1> <p class="verinfo">(No version information available, might be only in CVS)</p><p class="refpurpose"><span class="refname">PDOStatement->closeCursor</span> — <span class="dc-title"> Closes the cursor, enabling the statement to be executed again. </span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">bool</span> <span class="methodname"><b><b>PDOStatement::closeCursor</b></b></span> ( <span class="methodparam">void</span> )</div> <p class="para rdfs-comment"> <b>PDOStatement::closeCursor()</b> frees up the connection to the server so that other SQL statements may be issued, but leaves the statement in a state that enables it to be executed again. </p> <p class="para"> This method is useful for database drivers that do not support executing a PDOStatement object when a previously executed PDOStatement object still has unfetched rows. If your database driver suffers from this limitation, the problem may manifest itself in an out-of-sequence error. </p> <p class="para"> <b>PDOStatement::closeCursor()</b> is implemented either as an optional driver specific method (allowing for maximum efficiency), or as the generic PDO fallback if no driver specific function is installed. The PDO generic fallback is semantically the same as writing the following code in your PHP script: <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br /></span><span style="color: #007700">do {<br /> while (</span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-></span><span style="color: #0000BB">fetch</span><span style="color: #007700">())<br /> ;<br /> if (!</span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-></span><span style="color: #0000BB">nextRowset</span><span style="color: #007700">())<br /> break;<br />} while (</span><span style="color: #0000BB">true</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span></span></code></div> </div> </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns <b><tt>TRUE</tt></b> on success or <b><tt>FALSE</tt></b> on failure. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example"> <p><b>Example #1 A <b>PDOStatement::closeCursor()</b> example</b></p> <div class="example-contents"><p> In the following example, the <var class="varname">$stmt</var> PDOStatement object returns multiple rows but the application fetches only the first row, leaving the PDOStatement object in a state of having unfetched rows. To ensure that the application will work with all database drivers, the author inserts a call to <b>PDOStatement::closeCursor()</b> on <var class="varname">$stmt</var> before executing the <var class="varname">$otherStmt</var> PDOStatement object. </p></div> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">/* Create a PDOStatement object */<br /></span><span style="color: #0000BB">$stmt </span><span style="color: #007700">= </span><span style="color: #0000BB">$dbh</span><span style="color: #007700">-></span><span style="color: #0000BB">prepare</span><span style="color: #007700">(</span><span style="color: #DD0000">'SELECT foo FROM bar'</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* Create a second PDOStatement object */<br /></span><span style="color: #0000BB">$otherStmt </span><span style="color: #007700">= </span><span style="color: #0000BB">$dbh</span><span style="color: #007700">-></span><span style="color: #0000BB">prepare</span><span style="color: #007700">(</span><span style="color: #DD0000">'SELECT foobaz FROM foobar'</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">/* Execute the first statement */<br /></span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-></span><span style="color: #0000BB">execute</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* Fetch only the first row from the results */<br /></span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-></span><span style="color: #0000BB">fetch</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* The following call to closeCursor() may be required by some drivers */<br /></span><span style="color: #0000BB">$stmt</span><span style="color: #007700">-></span><span style="color: #0000BB">closeCursor</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* Now we can execute the second statement */<br /></span><span style="color: #0000BB">$otherStmt</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> </p> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="pdostatement.execute.html" class="function" rel="rdfs-seeAlso">PDOStatement::execute()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="pdostatement.bindvalue.html">PDOStatement->bindValue</a></div> <div class="next" style="text-align: right; float: right;"><a href="pdostatement.columncount.html">PDOStatement->columnCount</a></div> <div class="up"><a href="class.pdostatement.html">PDOStatement</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div></body></html>⌨️ 快捷键说明
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