Copyright 1997-2021 the PHP Documentation Group.
mysqli::query
mysqli_query
Performs a query on the database
Description
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 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.
Data inside the query should be properly escaped.
-
resultmode
Either the constant
MYSQLI_USE_RESULT
orMYSQLI_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 errorCommands out of sync
unless you callmysqli_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.
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 7.67 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
See Also
mysqli_real_query
|
mysqli_multi_query
|
mysqli_free_result
|