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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>pdo_stmt_t definition</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="internals2.pdo.pdo-dbh-t.html">pdo_dbh_t definition</a></div> <div class="next" style="text-align: right; float: right;"><a href="internals2.pdo.constants.html">Constants</a></div> <div class="up"><a href="internals2.pdo.html">PDO Driver How-To</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="internals2.pdo.pdo_stmt_t" class="sect1"> <h2 class="title">pdo_stmt_t definition</h2> <p class="para"> All fields should be treated as read-only unless explicitly stated otherwise. </p> <div class="figure"> <h1 class="title">pdo_stmt_t</h1> <div class="example-contents"><div class="cdata"><pre>/* represents a prepared statement */struct _pdo_stmt_t { /* driver specifics */ struct pdo_stmt_methods *methods; </pre></div><a name="internals2.pdo.stmt.co.methods" id="internals2.pdo.stmt.co.methods">*</a><div class="cdata"><pre> void *driver_data; </pre></div><a name="internals2.pdo.stmt.co.driver-data" id="internals2.pdo.stmt.co.driver-data">**</a><div class="cdata"><pre> /* if true, we've already successfully executed this statement at least * once */ unsigned executed:1; </pre></div><a name="internals2.pdo.stmt.co.executed" id="internals2.pdo.stmt.co.executed">***</a><div class="cdata"><pre> /* if true, the statement supports placeholders and can implement * bindParam() for its prepared statements, if false, PDO should * emulate prepare and bind on its behalf */ unsigned supports_placeholders:2; </pre></div><a name="internals2.pdo.stmt.co.holder" id="internals2.pdo.stmt.co.holder">****</a><div class="cdata"><pre> /* the number of columns in the result set; not valid until after * the statement has been executed at least once. In some cases, might * not be valid until fetch (at the driver level) has been called at least once. * */ int column_count; </pre></div><a name="internals2.pdo.stmt.co.colcount" id="internals2.pdo.stmt.co.colcount">*****</a><div class="cdata"><pre> struct pdo_column_data *columns; </pre></div><a name="internals2.pdo.stmt.co.cols" id="internals2.pdo.stmt.co.cols">******</a><div class="cdata"><pre> /* points at the dbh that this statement was prepared on */ pdo_dbh_t *dbh; /* keep track of bound input parameters. Some drivers support * input/output parameters, but you can't rely on that working */ HashTable *bound_params; /* When rewriting from named to positional, this maps positions to names */ HashTable *bound_param_map; /* keep track of PHP variables bound to named (or positional) columns * in the result set */ HashTable *bound_columns; /* not always meaningful */ long row_count; /* used to hold the statement's current query */ char *query_string; int query_stringlen; /* the copy of the query with expanded binds ONLY for emulated-prepare drivers */ char *active_query_string; int active_query_stringlen; /* the cursor specific error code. */ pdo_error_type error_code; /* used by the query parser for driver specific * parameter naming (see pgsql driver for example) */ const char *named_rewrite_template;}; </pre></div></div> </div> <table> <tr><td><a href="#internals2.pdo.stmt.co.methods">*</a></td><td> <p class="para"> The driver <em class="emphasis">must</em> set this during <b>SKEL_handle_preparer()</b>. </p> </td></tr> <tr><td><a href="#internals2.pdo.stmt.co.driver-data">**</a></td><td> <p class="para"> This item is for use by the driver; the intended usage is to store a pointer (during <b>SKEL_handle_factory()</b>) to whatever instance data is required to maintain a connection to the database. </p> </td></tr> <tr><td><a href="#internals2.pdo.stmt.co.executed">***</a></td><td> <p class="para"> This is set by PDO after the statement has been executed for the first time. Your driver can inspect this value to determine if it can skip one-time actions as an optimization. </p> </td></tr> <tr><td><a href="#internals2.pdo.stmt.co.holder">****</a></td><td> <p class="para"> Discussed in more detail in <a href="internals2.pdo.implementing.html" class="xref">Fleshing out your skeleton</a>. </p> </td></tr> <tr><td><a href="#internals2.pdo.stmt.co.colcount">*****</a></td><td> <p class="para"> Your driver is responsible for setting this field to the number of columns available in a result set. This is usually set during <b>SKEL_stmt_execute()</b> but with some database implementations, the column count may not be available until <b>SKEL_stmt_fetch()</b> has been called at least once. Drivers that implement <b>SKEL_stmt_next_rowset()</b> should update the column count when a new rowset is available. </p> </td></tr> <tr><td><a href="#internals2.pdo.stmt.co.cols">******</a></td><td> <p class="para"> PDO will allocate this field based on the value that you set for the column count. You are responsible for populating each column during <b>SKEL_stmt_describe()</b>. You must set the <i><tt class="parameter">precision</tt></i>, <i><tt class="parameter">maxlen</tt></i>, <i><tt class="parameter">name</tt></i>, <i><tt class="parameter">namelen</tt></i> and <i><tt class="parameter">param_type</tt></i> members for each column. The <i><tt class="parameter">name</tt></i> is expected to be allocated using <b>emalloc()</b>; PDO will call <b>efree()</b> at the appropriate time. </p> </td></tr> </table></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="internals2.pdo.pdo-dbh-t.html">pdo_dbh_t definition</a></div> <div class="next" style="text-align: right; float: right;"><a href="internals2.pdo.constants.html">Constants</a></div> <div class="up"><a href="internals2.pdo.html">PDO Driver How-To</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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