ORDER BY 子句，如前面的讨论所述，对语句的结果进行排序.它指定操作数据的顺序，并包括按升序(ASC)或降序(DESC)顺序排序的选项.在省略订单规范时，默认顺序是升序.
ORDER BY子句出现在各种语句中，例如DELETE和UPDATE.它们总是出现在语句的末尾，而不是在子查询中或在set函数之前，因为它们在最终结果表上运行.您也不能使用整数来标识列.
查看下面给出的ORDER BY子句的一般语法 :
SELECT field, field2,... [or column] FROM table_name, table_name2,... ORDER BY field, field2,... ASC[or DESC]
在命令提示符或PHP脚本中使用ORDER BY子句.
在命令提示符下，只需使用标准命令 :
root@ host# mysql -u root -p password; Enter password:******* mysql> use PRODUCTS; Database changed mysql> SELECT * from products_tbl ORDER BY product_manufacturer ASC +-------------+----------------+----------------------+ | ID_number | Nomenclature | product_manufacturer | +-------------+----------------+----------------------+ | 56789 | SuperBlast 400 | LMN Corp | +-------------+----------------+----------------------+ | 67891 | Zoomzoom 5000 | QFT Corp | +-------------+----------------+----------------------+ | 12347 | Orbitron 1000 | XYZ Corp | +-------------+----------------+----------------------+
利用 mysql_query ()函数，再一次，在使用ORDER BY子句的语句中减去;
<?php
$dbhost = 'localhost:3036';
$dbuser = 'root';
$dbpass = 'rootpassword';
$conn = mysql_connect($dbhost, $dbuser, $dbpass);
if(! $conn ) {
die('Could not connect: ' . mysql_error());
}
$sql = 'SELECT product_id, product_name, product_manufacturer, ship_date
FROM products_tbl ORDER BY product_manufacturer DESC';
mysql_select_db('PRODUCTS');
$retval = mysql_query( $sql, $conn );
if(! $retval ) {
die('Could not get data: ' . mysql_error());
}
while($row = mysql_fetch_array($retval, MYSQL_ASSOC)) {
echo "Product ID :{$row['product_id']} <br> ".
"Name: {$row['product_name']} <br> ".
"Manufacturer: {$row['product_manufacturer']} <br> ".
"Ship Date : {$row['ship_date']} <br> ".
"--------------------------------<br>";
}
echo "Fetched data successfully\n";
mysql_close($conn);
?>成功检索数据后，您将看到以下输出 :
Product ID: 12347 Nomenclature: Orbitron 1000 Manufacturer: XYZ Corp Ship Date: 01/01/17 ---------------------------------------------- Product ID: 67891 Nomenclature: Zoomzoom 5000 Manufacturer: QFT Corp Ship Date: 01/01/17 ---------------------------------------------- Product ID: 56789 Nomenclature: SuperBlast 400 Manufacturer: LMN Corp Ship Date: 01/04/17 ---------------------------------------------- mysql> Fetched data successfully
