mysqli_query
(PHP 5)
mysqli_query
(no version information, might be only in CVS)
mysqli->query -- Performs a query on the database
Description
Procedural style:
mixed
mysqli_query ( object link, string query [, int resultmode])
Object oriented style (method):
class
mysqli {
mixed
query ( string query)
}
The mysqli_query() function is used to simplify the
act of performing a query against the database represented by the
link parameter.
Functionally, using this
function is identical to calling mysqli_real_query()
followed either by mysqli_use_result() or
mysqli_store_result() where query
is the query string itself and resultmode is
either the constant MYSQLI_USE_RESULT or
MYSQLI_STORE_RESULT depending
on the desired behavior. By default, if the
resultmode is not provided
MYSQLI_STORE_RESULT is used.
If you execute mysqli_query() with resultmode
MYSQLI_USE_RESULT all subsequent calls will return error
Commands out of sync unless you call mysqli_free_result().
Return values
如果成功则返回 TRUE，失败则返回 FALSE。 For SELECT, SHOW, DESCRIBE or
EXPLAIN mysqli_query() will return
a result object.
Example
例子 1. 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();
?>
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例子 2. 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);
?>
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The above examples would produce the following output:
Table myCity successfully created.
Select returned 10 rows.
Error: Commands out of sync; You can't run this command now |