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子句的基本语法如下 :
SELECT column-list FROM table_name [WHERE condition] [ORDER BY column1,column2 ,. .colinN] [ASC | DESC];
您可以在ORDER BY子句中使用多个列.确保您用于对该列进行排序的列应位于列列表中.
考虑具有以下记录的CUSTOMERS表 :
+----+----------+-----+-----------+----------+ | 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 | +----+----------+-----+-----------+----------+
以下代码块有一个示例,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 | +----+----------+-----+-----------+----------+