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mysqli::query

mysqli_query

(PHP 5)

mysqli::query -- mysqli_queryPerforms a query on the database

Description

Object oriented style

mixed mysqli::query ( string $query [, int $resultmode = MYSQLI_STORE_RESULT ] )

Procedural style

mixed mysqli_query ( mysqli $link , string $query [, int $resultmode = MYSQLI_STORE_RESULT ] )

Performs a query against the database.

For non-DML queries (not INSERT, UPDATE or DELETE), this function is similar to calling mysqli_real_query() followed by either mysqli_use_result() or mysqli_store_result().

Note:

In the case where you pass a statement to mysqli_query() 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

link

Procedural style only: A link identifier returned by mysqli_connect() or mysqli_init()

query

The query string.

Data inside the query should be properly escaped.

resultmode

Either the constant MYSQLI_USE_RESULT or MYSQLI_STORE_RESULT depending on the desired behavior. By default, MYSQLI_STORE_RESULT is used.

If you use MYSQLI_USE_RESULT all subsequent calls will return error Commands out of sync unless you call mysqli_free_result()

With MYSQLI_ASYNC (available with mysqlnd), it is possible to perform query asynchronously. mysqli_poll() is then used to get results from such queries.

Return Values

Returns FALSE on failure. For successful SELECT, SHOW, DESCRIBE or EXPLAIN queries mysqli_query() will return a mysqli_result object. For other successful queries mysqli_query() will return TRUE.

Changelog

Version Description
5.3.0 Added the ability of async queries.

Examples

Example #1 mysqli::query example

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();
}

/* Create table doesn't return a resultset */
if ($mysqli->query("CREATE TEMPORARY TABLE myCity LIKE City") === TRUE) {
    
printf("Table myCity successfully created.\n");
}

/* Select queries return a resultset */
if ($result $mysqli->query("SELECT Name FROM City LIMIT 10")) {
    
printf("Select returned %d rows.\n"$result->num_rows);

    
/* free result set */
    
$result->close();
}

/* If we have to retrieve large amount of data we use MYSQLI_USE_RESULT */
if ($result $mysqli->query("SELECT * FROM City"MYSQLI_USE_RESULT)) {

    
/* Note, that we can't execute any functions which interact with the
       server until result set was closed. All calls will return an
       'out of sync' error */
    
if (!$mysqli->query("SET @a:='this will not work'")) {
        
printf("Error: %s\n"$mysqli->error);
    }
    
$result->close();
}

$mysqli->close();
?>

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();
}

/* Create table doesn't return a resultset */
if (mysqli_query($link"CREATE TEMPORARY TABLE myCity LIKE City") === TRUE) {
    
printf("Table myCity successfully created.\n");
}

/* Select queries return a resultset */
if ($result mysqli_query($link"SELECT Name FROM City LIMIT 10")) {
    
printf("Select returned %d rows.\n"mysqli_num_rows($result));

    
/* free result set */
    
mysqli_free_result($result);
}

/* If we have to retrieve large amount of data we use MYSQLI_USE_RESULT */
if ($result mysqli_query($link"SELECT * FROM City"MYSQLI_USE_RESULT)) {

    
/* Note, that we can't execute any functions which interact with the
       server until result set was closed. All calls will return an
       'out of sync' error */
    
if (!mysqli_query($link"SET @a:='this will not work'")) {
        
printf("Error: %s\n"mysqli_error($link));
    }
    
mysqli_free_result($result);
}

mysqli_close($link);
?>

The above examples will output:

Table myCity successfully created.
Select returned 10 rows.
Error: Commands out of sync;  You can't run this command now

See Also

PHP Manual