mysqli::query
mysqli_query
(PHP 5, PHP 7, PHP 8)
mysqli::query -- mysqli_query — Performs a query on the database
Beschreibung
Objektorientierter Stil
Prozeduraler Stil
$mysql
, string $query
, int $result_mode
= MYSQLI_STORE_RESULT
): mysqli_result|bool
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().
Hinweis:
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 meansgot a packet bigger than.max_allowed_packet
bytes
mysqlnd
on Windows returns an error code 2006. This error message meansserver has gone away.
libmysqlclient
on all platforms returns an error code 2006. This error message meansserver has gone away.
Parameter-Liste
-
mysql
-
Nur bei prozeduralem Aufruf: Ein von mysqli_connect() oder mysqli_init() zurückgegebenes mysqli-Objekt.
-
query
-
The query string.
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.
-
result_mode
-
The result mode can be one of 3 constants indicating how the result will be returned from the MySQL server.
MYSQLI_STORE_RESULT
(default) - returns a mysqli_result object with buffered result set.MYSQLI_USE_RESULT
- returns a mysqli_result object with unbuffered result set. As long as there are pending records waiting to be fetched, the connection line will be busy and all subsequent calls will return errorCommands out of sync
. To avoid the error all records must be fetched from the server or the result set must be discarded by calling mysqli_free_result().MYSQLI_ASYNC
(available with mysqlnd) - the query is performed asynchronously and no result set is immediately returned. mysqli_poll() is then used to get results from such queries. Used in combination with eitherMYSQLI_STORE_RESULT
orMYSQLI_USE_RESULT
constant.
Rückgabewerte
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
.
Beispiele
Beispiel #1 mysqli::query() example
Objektorientierter Stil
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* Create table doesn't return a resultset */
$mysqli->query("CREATE TEMPORARY TABLE myCity LIKE City");
printf("Table myCity successfully created.\n");
/* Select queries return a resultset */
$result = $mysqli->query("SELECT Name FROM City LIMIT 10");
printf("Select returned %d rows.\n", $result->num_rows);
/* If we have to retrieve large amount of data we use MYSQLI_USE_RESULT */
$result = $mysqli->query("SELECT * FROM City", MYSQLI_USE_RESULT);
/* Note, that we can't execute any functions which interact with the
server until all records have been fully retrieved or the result
set was closed. All calls will return an 'out of sync' error */
$mysqli->query("SET @a:='this will not work'");
Prozeduraler Stil
<?php
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* Create table doesn't return a resultset */
mysqli_query($link, "CREATE TEMPORARY TABLE myCity LIKE City");
printf("Table myCity successfully created.\n");
/* Select queries return a resultset */
$result = mysqli_query($link, "SELECT Name FROM City LIMIT 10");
printf("Select returned %d rows.\n", mysqli_num_rows($result));
/* If we have to retrieve large amount of data we use MYSQLI_USE_RESULT */
$result = mysqli_query($link, "SELECT * FROM City", MYSQLI_USE_RESULT);
/* Note, that we can't execute any functions which interact with the
server until all records have been fully retrieved or the result
set was closed. All calls will return an 'out of sync' error */
mysqli_query($link, "SET @a:='this will not work'");
Die oben gezeigten Beispiele erzeugen eine ähnliche Ausgabe wie:
Table myCity successfully created. Select returned 10 rows. Fatal error: Uncaught mysqli_sql_exception: Commands out of sync; you can't run this command now in...
Siehe auch
- mysqli_real_query() - Execute an SQL query
- mysqli_multi_query() - Performs one or more queries on the database
- mysqli_prepare() - Prepares an SQL statement for execution
- mysqli_free_result() - Frees the memory associated with a result