7.3.8.37 mysqli::query, mysqli_query

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• mysqli::query

  mysqli_query

  Performs a query on the database

Description

Object oriented style

public 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 queries which produce a result set, such as SELECT, SHOW, DESCRIBE or EXPLAIN, mysqli_query will return a mysqli_result object. For other successful queries, mysqli_query will return true.

Examples

Example 7.67 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

mysqli_real_query

mysqli_multi_query

mysqli_free_result