mysqli::prepare
mysqli_prepare
(PHP 5, PHP 7, PHP 8)
mysqli::prepare -- mysqli_prepare — Prepares an SQL statement for execution
Description
Object-oriented style
Procedural style
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 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.
Parameters
-
mysql
-
Procedural style only: A mysqli object returned by mysqli_connect() or mysqli_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 anINSERT
statement (to specify column values for a row), or in a comparison with a column in aWHERE
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
mysqli_prepare() returns a statement object or false
if an error occurred.
Examples
Example #1 mysqli::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->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 */
$stmt = mysqli_prepare($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);
The above examples will output:
Amersfoort is in district Utrecht
See Also
- mysqli_stmt_execute() - Executes a prepared statement
- mysqli_stmt_fetch() - Fetch results from a prepared statement into the bound variables
- mysqli_stmt_bind_param() - Binds variables to a prepared statement as parameters
- mysqli_stmt_bind_result() - Binds variables to a prepared statement for result storage
- mysqli_stmt_get_result() - Gets a result set from a prepared statement as a mysqli_result object
- mysqli_stmt_close() - Closes a prepared statement