Copyright 1997-2021 the PHP Documentation Group.
mysqli::query
mysqli_query
Performs a query on the database
Description
Object oriented style
public mysqli_result|bool mysqli::query(string query,
int result_mode= =MYSQLI_STORE_RESULT);
Procedural style
mysqli_result|bool mysqli_query(mysqli mysql,
string query,
int result_mode= =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
.
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 thanmax_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
ormysqli_init
-
query
The query string.
Security warning: SQL injectionIf 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.-
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 amysqli_result
object with buffered result set.MYSQLI_USE_RESULT
- returns amysqli_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 callingmysqli_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.
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 3.59 mysqli::query
example
Object oriented style
<?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'");
Procedural style
<?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'");
The above examples will output something similar to:
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...
See Also
mysqli_real_query
|
mysqli_multi_query
|
mysqli_prepare
|
mysqli_free_result
|