SQL ORDER BY 子句用于根据一列或多列按升序或降序对数据进行排序.默认情况下，某些数据库按升序对查询结果进行排序.
ORDER BY子句的基本语法，用于排序升序或降序的结果如下:<
SELECT column-list FROM table_name [WHERE条件] [ORDER BY column1，column2，.. columnN] [ASC | DESC];
您可以在ORDER BY子句中使用多个列.确保您用于排序的列，该列应该在列列表中.
考虑CUSTOMERS表具有以下记录 :
+----+----------+-----+-----------+----------+ | ID | NAME | AGE | ADDRESS | SALARY | +----+----------+-----+-----------+----------+ | 1 | Ramesh | 32 | Ahmedabad | 2000.00 | | 2 | Khilan | 25 | Delhi | 1500.00 | | 3 | kaushik | 23 | Kota | 2000.00 | | 4 | Chaitali | 25 | Mumbai | 6500.00 | | 5 | Hardik | 27 | Bhopal | 8500.00 | | 6 | Komal | 22 | MP | 4500.00 | | 7 | Muffy | 24 | Indore | 10000.00 | +----+----------+-----+-----------+----------+
以下是一个例子，它将按照NAME和SALARY的升序对结果进行排序.
SQL> SELECT * FROM CUSTOMERS ORDER BY NAME，SALARY;
这会产生以下结果 :
+----+----------+-----+-----------+----------+ | ID | NAME | AGE | ADDRESS | SALARY | +----+----------+-----+-----------+----------+ | 4 | Chaitali | 25 | Mumbai | 6500.00 | | 5 | Hardik | 27 | Bhopal | 8500.00 | | 3 | kaushik | 23 | Kota | 2000.00 | | 2 | Khilan | 25 | Delhi | 1500.00 | | 6 | Komal | 22 | MP | 4500.00 | | 7 | Muffy | 24 | Indore | 10000.00 | | 1 | Ramesh | 32 | Ahmedabad | 2000.00 | +----+----------+-----+-----------+----------+
以下代码块有一个示例，它将按照NAME的降序对结果进行排序.
SQL> SELECT * FROM CUSTOMERS ORDER BY NAME DESC;
这会产生以下结果 :
+----+----------+-----+-----------+----------+ | ID | NAME | AGE | ADDRESS | SALARY | +----+----------+-----+-----------+----------+ | 1 | Ramesh | 32 | Ahmedabad | 2000.00 | | 7 | Muffy | 24 | Indore | 10000.00 | | 6 | Komal | 22 | MP | 4500.00 | | 2 | Khilan | 25 | Delhi | 1500.00 | | 3 | kaushik | 23 | Kota | 2000.00 | | 5 | Hardik | 27 | Bhopal | 8500.00 | | 4 | Chaitali | 25 | Mumbai | 6500.00 | +----+----------+-----+-----------+----------+
要使用自己的首选顺序获取行，使用的SELECT查询将如下 :
SQL> SELECT * FROM CUSTOMERS ORDER BY (CASE ADDRESS WHEN 'DELHI' THEN 1 WHEN 'BHOPAL' THEN 2 WHEN 'KOTA' THEN 3 WHEN 'AHMADABAD' THEN 4 WHEN 'MP' THEN 5 ELSE 100 END) ASC, ADDRESS DESC;
这会产生以下结果 :
+----+----------+-----+-----------+----------+ | ID | NAME | AGE | ADDRESS | SALARY | +----+----------+-----+-----------+----------+ | 2 | Khilan | 25 | Delhi | 1500.00 | | 5 | Hardik | 27 | Bhopal | 8500.00 | | 3 | kaushik | 23 | Kota | 2000.00 | | 6 | Komal | 22 | MP | 4500.00 | | 4 | Chaitali | 25 | Mumbai | 6500.00 | | 7 | Muffy | 24 | Indore | 10000.00 | | 1 | Ramesh | 32 | Ahmedabad | 2000.00 | +----+----------+-----+-----------+----------+
这将首先按照您的 ownoOrder 中的ADDRESS对客户进行排序，并按自然顺序对其余地址进行排序.此外，剩余的地址将按反向字母顺序排序.
