7.3.8.31 mysqli::multi_query, mysqli_multi_query

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• mysqli::multi_query

  mysqli_multi_query

  Performs one or more queries on the database

Description

Object-oriented style

public bool mysqli::multi_query(string query);

Procedural style

bool mysqli_multi_query(mysqli mysql,
                        string query);

Executes one or multiple queries which are concatenated by a semicolon.

Queries are sent asynchronously in a single call to the database, but the database processes them sequentially. mysqli_multi_query waits for the first query to complete before returning control to PHP. The MySQL server will then process the next query in the sequence. Once the next result is ready, MySQL will wait for the next execution of mysqli_next_result from PHP.

It is recommended to use do-while to process multiple queries. The connection will be busy until all queries have completed and their results are fetched to PHP. No other statement can be issued on the same connection until all queries are processed. To proceed to the next query in the sequence, use mysqli_next_result. If the next result is not ready yet, mysqli will wait for the response from the MySQL server. To check if there are more results, use mysqli_more_results.

For queries which produce a result set, such as SELECT, SHOW, DESCRIBE or EXPLAIN, mysqli_use_result or mysqli_store_result can be used to retrieve the result set. For queries which do not produce a result set, the same functions can be used to retrieve information such as the number of affected rows.

Tip

Executing CALL statements for stored procedures can produce multiple result sets. If the stored procedure contains SELECT statements, the result sets are returned in the order that they are produced as the procedure executes. In general, the caller cannot know how many result sets a procedure will return and must be prepared to retrieve multiple results. The final result from the procedure is a status result that includes no result set. The status indicates whether the procedure succeeded or an error occurred.

Parameters

mysql

Procedural style only: A mysqli object returned by mysqli_connect or mysqli_init

query

A string containing the queries to be executed. Multiple queries must be separated by a semicolon.

Security warning: SQL injection

If the query contains any variable input then parameterized prepared statements should be used instead. Alternatively, the data must be properly formatted and all strings must be escaped using the mysqli_real_escape_string function.

Return Values

Returns false if the first statement failed. To retrieve subsequent errors from other statements you have to call mysqli_next_result first.

Examples

Example 7.63 mysqli::multi_query example

Object-oriented style

<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
$query = "SELECT CURRENT_USER();";
$query .= "SELECT Name FROM City ORDER BY ID LIMIT 20, 5";
/* execute multi query */
$mysqli->multi_query($query);
do {
    /* store the result set in PHP */
    if ($result = $mysqli->store_result()) {
        while ($row = $result->fetch_row()) {
            printf("%s\n", $row[0]);
        }
    }
    /* print divider */
    if ($mysqli->more_results()) {
        printf("-----------------\n");
    }
} while ($mysqli->next_result());

Procedural style

<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
$query = "SELECT CURRENT_USER();";
$query .= "SELECT Name FROM City ORDER BY ID LIMIT 20, 5";
/* execute multi query */
mysqli_multi_query($link, $query);
do {
    /* store the result set in PHP */
    if ($result = mysqli_store_result($link)) {
        while ($row = mysqli_fetch_row($result)) {
            printf("%s\n", $row[0]);
        }
    }
    /* print divider */
    if (mysqli_more_results($link)) {
        printf("-----------------\n");
    }
} while (mysqli_next_result($link));

The above examples will output something similar to:

my_user@localhost
-----------------
Amersfoort
Maastricht
Dordrecht
Leiden
Haarlemmermeer

See Also

mysqli_query

mysqli_use_result

mysqli_store_result

mysqli_next_result

mysqli_more_results