MySQL and PHP
Copyright 1997-2021 the PHP Documentation Group.
mysqli::query
mysqli_query
Performs a query on the database
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
.
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”.
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.
Returns false
on failure. For successful
SELECT, SHOW, DESCRIBE
or
EXPLAIN
queries
mysqli_query
will return a mysqli_result
object. For
other successful queries
mysqli_query
will return true
.
Example 3.60 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
mysqli_real_query
|
mysqli_multi_query
|
mysqli_free_result
|