mysqli_stmt->param_count
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MySQLi_STMT
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# mysqli_stmt::prepare

# mysqli_stmt_prepare

(PHP 5)

mysqli_stmt::prepare -- mysqli_stmt_prepare — Prepare a SQL statement for execution

### Descripción

Object oriented style (method)

mixed mysqli_stmt::prepare ( string `$query` )

Procedure style:

bool mysqli_stmt_prepare ( mysqli_stmt `$stmt` , string `$query` )

Prepares the SQL query pointed to by the null-terminated string query.

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.

### Lista de parámetros

`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.

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

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

  > 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. In general, parameters are legal only in Data Manipulation Language (DML) statements, and not in Data Definition Language (DDL) statements.

### Valores retornados

Devuelve `TRUE` si todo se llevó a cabo correctamente, `FALSE` en caso de fallo.

### Ejemplos

Example #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 */
$stmt = $mysqli->stmt_init();
if ($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);
/* close statement */
$stmt->close();
}
/* close connection */
$mysqli->close();
?>`

Example #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 */
$stmt = mysqli_stmt_init($link);
if (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, $district);
/* close statement */
mysqli_stmt_close($stmt);
}
/* close connection */
mysqli_close($link);
?>`

El resultado del ejemplo seria:

    Amersfoort is in district Utrecht

### Ver también

mysqli_stmt_init() - Initializes a statement and returns an object for use with mysqli_stmt_prepare, mysqli_stmt_execute() - Executes a prepared Query, 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_close() - Closes a prepared statement.

mysqli_stmt->param_count
mysqli_stmt::reset
MySQLi_STMT
PHP Manual