PostgreSQL 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];
您可以在 ORDER BY 子句中使用多个列。确保您使用的任何列进行排序，该列应该在列列表中可用。
例子
考虑表pgccc_COMPANY 的记录如下
LNXDB# select * from pgccc_COMPANY; id | name | age | address | salary ‐‐‐+‐‐‐‐‐‐‐+‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐ 1 | Paul | 32 | California| 20000 2 | Allen | 25 | Texas | 15000 3 | Teddy | 23 | Norway | 20000 4 | Mark | 25 | Rich‐Mond | 65000 5 | David | 27 | Texas | 85000 6 | Kim | 22 | South‐Hall| 45000 7 | James | 24 | Houston | 10000 (7 rows)
以下是一个示例，它将按 SALARY 按升序对结果进行排序
LNXDB=# SELECT * FROM pgccc_COMPANY ORDER BY AGE ASC;
这将产生以下结果
id | name | age | address | salary ‐‐‐‐+‐‐‐‐‐‐‐+‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐ 6 | Kim | 22 | South‐Hall | 45000 3 | Teddy | 23 | Norway | 20000 7 | James | 24 | Houston | 10000 8 | Paul | 24 | Houston | 20000 4 | Mark | 25 | Rich‐Mond | 65000 2 | Allen | 25 | Texas | 15000 5 | David | 27 | Texas | 85000 1 | Paul | 32 | California | 20000 9 | James | 44 | Norway | 5000 10 | James | 45 | Texas | 5000 (10 rows)
以下是一个示例，它将按 NAME 和 SALARY 按升序对结果进行排序
LNXDB=# SELECT * FROM pgccc_COMPANY ORDER BY NAME, SALARY ASC;
这将产生以下结果
id | name | age | address | salary ‐‐‐+‐‐‐‐‐‐‐+‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐ 2 | Allen | 25 | Texas | 15000 5 | David | 27 | Texas | 85000 10 | James | 45 | Texas | 5000 9 | James | 44 | Norway | 5000 7 | James | 24 | Houston | 10000 6 | Kim | 22 | South‐Hall | 45000 4 | Mark | 25 | Rich‐Mond | 65000 1 | Paul | 32 | California | 20000 8 | Paul | 24 | Houston | 20000 3 | Teddy | 23 | Norway | 20000 (10 rows)
以下是一个示例，它将按 NAME 按降序对结果进行排序
LNXDB=# SELECT * FROM pgccc_COMPANY ORDER BY NAME DESC;
这将产生以下结果
id | name | age | address | salary ‐‐‐‐+‐‐‐‐‐‐‐+‐‐‐‐‐+‐‐‐‐‐‐‐‐‐‐‐‐+‐‐‐‐‐‐‐‐ 3 | Teddy | 23 | Norway | 20000 1 | Paul | 32 | California | 20000 8 | Paul | 24 | Houston | 20000 4 | Mark | 25 | Rich‐Mond | 65000 6 | Kim | 22 | South‐Hall | 45000 7 | James | 24 | Houston | 10000 9 | James | 44 | Norway | 5000 10 | James | 45 | Texas | 5000 5 | David | 27 | Texas | 85000 2 | Allen | 25 | Texas | 15000 (10 rows)