mysqli::multi_query
mysqli_multi_query
(PHP 5, PHP 7, PHP 8)
mysqli::multi_query -- mysqli_multi_query — Performs one or more queries on the database
Beschreibung
Objektorientierter Stil
$query): boolProzeduraler Stil
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.
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.
Parameter-Liste
-
mysql -
Nur bei prozeduralem Aufruf: Ein von mysqli_connect() oder mysqli_init() zurückgegebenes mysqli-Objekt.
-
query -
A string containing the queries to be executed. Multiple queries must be separated by a semicolon.
WarnungSicherheitswarnung: SQL-Injection
Wenn die Abfrage irgendwelche Eingabevariablen enthält, sollten stattdessen parametrisierte Prepared Statements verwendet werden. Alternativ dazu müssen die Daten korrekt formatiert sein und alle Strings müssen mit der Funktion mysqli_real_escape_string() maskiert werden.
Rückgabewerte
Returns false if the first statement failed.
To retrieve subsequent errors from other statements you have to call
mysqli_next_result() first.
Beispiele
Beispiel #1 mysqli::multi_query() example
Objektorientierter Stil
<?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());
Prozeduraler Stil
<?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));
Die oben gezeigten Beispiele erzeugen eine ähnliche Ausgabe wie:
my_user@localhost ----------------- Amersfoort Maastricht Dordrecht Leiden Haarlemmermeer
Siehe auch
- mysqli_query() - Performs a query on the database
- mysqli_use_result() - Initiate a result set retrieval
- mysqli_store_result() - Transfers a result set from the last query
- mysqli_next_result() - Prepare next result from multi_query
- mysqli_more_results() - Check if there are any more query results from a multi query
