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mysqli::prepare

mysqli_prepare

(PHP 5)

mysqli::prepare -- mysqli_preparePrepare an SQL statement for execution

说明

面向对象风格

mysqli_stmt mysqli::prepare ( string $query )

过程化风格

mysqli_stmt mysqli_prepare ( mysqli $link , string $query )

Prepares the SQL query, and returns a statement handle to be used for further operations on the statement. The query must consist of a single SQL statement.

The parameter markers must be bound to application variables using mysqli_stmt_bind_param() and/or mysqli_stmt_bind_result() before executing the statement or fetching rows.

参数

link

仅以过程化样式:由 mysqli_connect()mysqli_init() 返回的链接标识。

query

The query, as a string.

Note:

You should not add a terminating semicolon or \g to the statement.

This parameter can include one or more parameter markers in the SQL statement by embedding question mark (?) characters at the appropriate positions.

Note:

The markers are legal only in certain places in SQL statements. For example, they are allowed in the VALUES() list of an INSERT statement (to specify column values for a row), or in a comparison with a column in a WHERE clause to specify a comparison value.

However, they are not allowed for identifiers (such as table or column names), in the select list that names the columns to be returned by a SELECT statement, or to specify both operands of a binary operator such as the = equal sign. The latter restriction is necessary because it would be impossible to determine the parameter type. It's not allowed to compare marker with NULL by ? IS NULL too. In general, parameters are legal only in Data Manipulation Language (DML) statements, and not in Data Definition Language (DDL) statements.

返回值

mysqli_prepare() returns a statement object or FALSE if an error occurred.

范例

Example #1 mysqli::prepare() example

面向对象风格

<?php
$mysqli 
= new mysqli("localhost""my_user""my_password""world");

/* check connection */
if (mysqli_connect_errno()) {
    
printf("Connect failed: %s\n"mysqli_connect_error());
    exit();
}

$city "Amersfoort";

/* create a prepared statement */
if ($stmt $mysqli->prepare("SELECT District FROM City WHERE Name=?")) {

    
/* bind parameters for markers */
    
$stmt->bind_param("s"$city);

    
/* execute query */
    
$stmt->execute();

    
/* bind result variables */
    
$stmt->bind_result($district);

    
/* fetch value */
    
$stmt->fetch();

    
printf("%s is in district %s\n"$city$district);

    
/* close statement */
    
$stmt->close();
}

/* close connection */
$mysqli->close();
?>

过程化风格

<?php
$link 
mysqli_connect("localhost""my_user""my_password""world");

/* check connection */
if (mysqli_connect_errno()) {
    
printf("Connect failed: %s\n"mysqli_connect_error());
    exit();
}

$city "Amersfoort";

/* create a prepared statement */
if ($stmt mysqli_prepare($link"SELECT District FROM City WHERE Name=?")) {

    
/* bind parameters for markers */
    
mysqli_stmt_bind_param($stmt"s"$city);

    
/* execute query */
    
mysqli_stmt_execute($stmt);

    
/* bind result variables */
    
mysqli_stmt_bind_result($stmt$district);

    
/* fetch value */
    
mysqli_stmt_fetch($stmt);

    
printf("%s is in district %s\n"$city$district);

    
/* close statement */
    
mysqli_stmt_close($stmt);
}

/* close connection */
mysqli_close($link);
?>

以上例程会输出:

Amersfoort is in district Utrecht

参见


MySQLi
PHP 手册