Prepare an SQL statement for execution

# maxdb_prepare

# maxdb::prepare

(PECL maxdb >= 1.0)

maxdb_prepare -- maxdb::prepare — Prepare an SQL statement for execution

### Descrierea

Stil procedural

maxdb_prepare ( resource `$link` , string `$query` ) : resource

Stil obiect-orientat

maxdb::prepare ( string `$query` ) : maxdb_stmt

maxdb_prepare() 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.

> Notă:

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

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

> Notă:

> 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 Languange (DML) statements, and not in Data Defination Language (DDL) statements.

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

### Valorile întoarse

maxdb_prepare() returns a statement resource or `FALSE` if an error occurred.

### Exemple

Example #1 Stil obiect-orientat

`<?php
$maxdb = new maxdb("localhost", "MONA", "RED", "DEMODB");
/* check connection */
if (maxdb_connect_errno()) {
printf("Connect failed: %s\n", maxdb_connect_error());
exit();
}
$city = "Rosemont";
/* create a prepared statement */
if ($stmt = $maxdb->prepare("SELECT state FROM hotel.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 */
$maxdb->close();
?>`

Example #2 Stil procedural

`<?php
$link = maxdb_connect("localhost", "MONA", "RED", "DEMODB");
/* check connection */
if (maxdb_connect_errno()) {
printf("Connect failed: %s\n", maxdb_connect_error());
exit();
}
$city = "Rosemont";
/* create a prepared statement */
if ($stmt = maxdb_prepare($link, "SELECT state FROM hotel.city WHERE name=?")) {
/* bind parameters for markers */
maxdb_stmt_bind_param($stmt, "s", $city);
/* execute query */
maxdb_stmt_execute($stmt);
/* bind result variables */
maxdb_stmt_bind_result($stmt, $district);
/* fetch value */
maxdb_stmt_fetch($stmt);
printf("%s is in district %s\n", $city, $district);
/* close statement */
maxdb_stmt_close($stmt);
}
/* close connection */
maxdb_close($link);
?>`

Exemplul de mai sus va afișa ceva similar cu:

    Rosemont is in district IL

### A se vedea și

- maxdb_stmt_execute() - Executes a prepared Query
- maxdb_stmt_fetch() - Fetch results from a prepared statement into the bound variables
- maxdb_stmt_bind_param() - Binds variables to a prepared statement as parameters
- maxdb_stmt_bind_result() - Binds variables to a prepared statement for result storage
- maxdb_stmt_close() - Closes a prepared statement