PHP: mysqli::stmt_init - Manual (original) (raw)
mysqli_stmt_init
(PHP 5, PHP 7, PHP 8)
mysqli::stmt_init -- mysqli_stmt_init — Initializes a statement and returns an object for use with mysqli_stmt_prepare
Description
Object-oriented style
Note:
Any subsequent calls to any mysqli_stmt function will fail until mysqli_stmt_prepare() was called.
Return Values
Returns an object.
Found A Problem?
9 years ago
stmt_init() seems to clear previous (possibly erroneous) results on the DB connection, which means you don't necessarily need to use it but it could make the code more robust.
In a PHPUnit test, I had a sequence of prepared queries on the same connection. One of them fetched a row from a SELECT but didn't keep fetching until it drained the connection, so it left some stale results. When the next query did this:
<?php <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>d</mi><mi>b</mi><mo>=</mo></mrow><annotation encoding="application/x-tex">db = </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">d</span><span class="mord mathnormal">b</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span></span></span></span>this->getConnection()->getDbConnection(); <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>p</mi><mi>r</mi><mi>e</mi><mi>p</mi><mi>a</mi><mi>r</mi><mi>e</mi><mi>d</mi><mi>Q</mi><mi>u</mi><mi>e</mi><mi>r</mi><mi>y</mi><mo>=</mo></mrow><annotation encoding="application/x-tex">preparedQuery = </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">p</span><span class="mord mathnormal">re</span><span class="mord mathnormal">p</span><span class="mord mathnormal">a</span><span class="mord mathnormal">re</span><span class="mord mathnormal">d</span><span class="mord mathnormal">Q</span><span class="mord mathnormal">u</span><span class="mord mathnormal" style="margin-right:0.03588em;">ery</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span></span></span></span>db->prepare ($query);
?>
the prepare() call generated an error: "Could not prepare query: Commands out of sync; you can't run this command now." Changing to this:
<?php <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>d</mi><mi>b</mi><mo>=</mo></mrow><annotation encoding="application/x-tex">db = </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6944em;"></span><span class="mord mathnormal">d</span><span class="mord mathnormal">b</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span></span></span></span>this->getConnection()->getDbConnection(); <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>p</mi><mi>r</mi><mi>e</mi><mi>p</mi><mi>a</mi><mi>r</mi><mi>e</mi><mi>d</mi><mi>Q</mi><mi>u</mi><mi>e</mi><mi>r</mi><mi>y</mi><mo>=</mo></mrow><annotation encoding="application/x-tex">preparedQuery = </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">p</span><span class="mord mathnormal">re</span><span class="mord mathnormal">p</span><span class="mord mathnormal">a</span><span class="mord mathnormal">re</span><span class="mord mathnormal">d</span><span class="mord mathnormal">Q</span><span class="mord mathnormal">u</span><span class="mord mathnormal" style="margin-right:0.03588em;">ery</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span></span></span></span>db->stmt_init(); <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>p</mi><mi>r</mi><mi>e</mi><mi>p</mi><mi>a</mi><mi>r</mi><mi>e</mi><mi>d</mi><mi>Q</mi><mi>u</mi><mi>e</mi><mi>r</mi><mi>y</mi><mo>−</mo><mo>></mo><mi>p</mi><mi>r</mi><mi>e</mi><mi>p</mi><mi>a</mi><mi>r</mi><mi>e</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">preparedQuery->prepare (</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.8889em;vertical-align:-0.1944em;"></span><span class="mord mathnormal">p</span><span class="mord mathnormal">re</span><span class="mord mathnormal">p</span><span class="mord mathnormal">a</span><span class="mord mathnormal">re</span><span class="mord mathnormal">d</span><span class="mord mathnormal">Q</span><span class="mord mathnormal">u</span><span class="mord mathnormal" style="margin-right:0.03588em;">ery</span><span class="mord">−</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">></span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal">p</span><span class="mord mathnormal">re</span><span class="mord mathnormal">p</span><span class="mord mathnormal">a</span><span class="mord mathnormal">re</span><span class="mopen">(</span></span></span></span>query);
?>
resolved the problem.11 years ago
you can use <span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>s</mi><mi>t</mi><mi>m</mi><mi>t</mi><mo>=</mo></mrow><annotation encoding="application/x-tex">stmt = </annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:0.6151em;"></span><span class="mord mathnormal">s</span><span class="mord mathnormal">t</span><span class="mord mathnormal">m</span><span class="mord mathnormal">t</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span></span></span></span>mysqli->prepare(); directly without stmt-init() . i think there is no need for stmt-init .