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PHP5中文手册

mysqli_query

mysqli->query()

(PHP 5)

mysqli->query() — Performs a query on the database

说明

Procedural style:

mixed mysqli_query ( mysqli $link , string $query [, int $resultmode ] )

Object oriented style (method):

mysqli
mixed query ( string $query [, int $resultmode ] )

Performs a query against the database.

Functionally, using this function is identical to calling mysqli_real_query() followed either by mysqli_use_result() or mysqli_store_result().

参数

link

Procedural style only: A link identifier returned by mysqli_connect() or mysqli_init()

query

The query string.

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()

返回值

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.

范例

Example#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();
?>

Example#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);
?>

上例将输出:

Table myCity successfully created.
Select returned 10 rows.
Error: Commands out of sync;  You can't run this command now