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mysqli_prepare (PHP 5) mysqli_prepare (no version information, might be only in CVS) mysqli->prepare() -- Prepare a SQL statement for execution 说明Procedure style: mysqli_stmt mysqli_prepare ( mysqli link, string query ) Object oriented style (method) class mysqli { mysqli_stmt prepare ( string query ) }
Prepares the SQL query pointed to by the null-terminated string 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
linkProcedural style only: A link identifier
returned by mysqli_connect() or mysqli_init()
query
The query, as a string.
注意:
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.
注意:
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 Languange (DML) statements, and not in Data
Defination Language (DDL) statements.
返回值
mysqli_prepare() returns a statement object or FALSE if an error occured.
范例例 1. Object oriented style <?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();
?> |
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例 2. Procedural style <?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);
?> |
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上例将输出: Amersfoort is in district Utrecht |
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