SQL ORDER BY 子句
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。
语法
ORDER BY 子句的基本语法如下:
SELECT column-list FROM table_name [WHERE condition] [ORDER BY column1, column2, .. columnN] [ASC | DESC];
你可以在 ORDER BY 子句中使用多个列,确保你用来对该列进行排序的任何列都应该在列列表中。
例子
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 | +----+----------+-----+-----------+----------+
下面的代码块有一个例子,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;
这将产生以下结果:
+----+----------+-----+-----------+----------+ | 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 | +----+----------+-----+-----------+----------+
下面的代码块有一个示例,它将按 NAME 按降序对结果进行排序。
SQL> SELECT * FROM CUSTOMERS ORDER BY NAME DESC;
这将产生以下结果:
+----+----------+-----+-----------+----------+ | 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 | +----+----------+-----+-----------+----------+