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7.3.9.23 mysqli_stmt::prepare, mysqli_stmt_prepare

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  • mysqli_stmt::prepare

    mysqli_stmt_prepare

    Prepares an SQL statement for execution

Description

Object oriented style

public bool mysqli_stmt::prepare(string query);

Procedural style

bool mysqli_stmt_prepare(mysqli_stmt statement,
                         string query);

Prepares a statement for execution. The query must consist of a single SQL statement.

The statement template can contain zero or more question mark (?) parameter markers⁠—also called placeholders. The parameter markers must be bound to application variables using mysqli_stmt_bind_param before executing the statement.

Note

In the case where you pass a statement to mysqli_stmt_prepare that is longer than max_allowed_packet of the server, the returned error codes are different depending on whether you are using MySQL Native Driver (mysqlnd) or MySQL Client Library (libmysqlclient). The behavior is as follows:

  • mysqlnd on Linux returns an error code of 1153. The error message means got a packet bigger than max_allowed_packet bytes.

  • mysqlnd on Windows returns an error code 2006. This error message means server has gone away.

  • libmysqlclient on all platforms returns an error code 2006. This error message means server has gone away.

Parameters

stmt

Procedural style only: A statement identifier returned by mysqli_stmt_init.

query

The query, as a string. It must consist of a single SQL statement.

The SQL statement may contain zero or more parameter markers represented by question mark (?) characters at the appropriate positions.

Note

The markers are legal only in certain places in SQL statements. For example, they are permitted 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 permitted for identifiers (such as table or column names), 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. In general, parameters are legal only in Data Manipulation Language (DML) statements, and not in Data Definition Language (DDL) statements.

Return Values

Returns true on success or false on failure.

Examples

Example 7.101 mysqli_stmt::prepare example

Object oriented style

<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
$city = "Amersfoort";
/* create a prepared statement */
$stmt = $mysqli->stmt_init();
$stmt->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);

Procedural style

<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
$city = "Amersfoort";
/* create a prepared statement */
$stmt = mysqli_stmt_init($link);
mysqli_stmt_prepare($stmt, "SELECT District FROM City WHERE Name=?");
/* bind parameters for markers */
mysqli_stmt_bind_param($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);

The above examples will output:

Amersfoort is in district Utrecht


See Also

mysqli_stmt_init
mysqli_stmt_execute
mysqli_stmt_fetch
mysqli_stmt_bind_param
mysqli_stmt_bind_result
mysqli_stmt_get_result
mysqli_stmt_close