如果我们要更新在 PostgreSQL 数据库中的数据,我们可以用 UPDATE 来操作。
以下是 UPDATE 语句修改数据的通用 SQL 语法:
UPDATE table_name SET column1 = value1, column2 = value2...., columnN = valueN WHERE [condition];
创建 COMPANY 表(下载 COMPANY SQL 文件 ),数据内容如下:
runoobdb# select * from 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)
以下实例将更新 COMPANY 表中 id 为 3 的 salary 字段值:
runoobdb=# UPDATE COMPANY SET SALARY = 15000 WHERE ID = 3;
得到结果如下:
id | name | age | address | salary ----+-------+-----+------------+-------- 1 | Paul | 32 | California | 20000 2 | Allen | 25 | Texas | 15000 4 | Mark | 25 | Rich-Mond | 65000 5 | David | 27 | Texas | 85000 6 | Kim | 22 | South-Hall | 45000 7 | James | 24 | Houston | 10000 3 | Teddy | 23 | Norway | 15000
从结果上看,COMPANY 表中的 id 为 3 的 salary 字段值已被修改。
以下实例将同时更新 salary 字段和 address 字段的值:
runoobdb=# UPDATE COMPANY SET ADDRESS = 'Texas', SALARY=20000;
得到结果如下:
id | name | age | address | salary ----+-------+-----+---------+-------- 1 | Paul | 32 | Texas | 20000 2 | Allen | 25 | Texas | 20000 4 | Mark | 25 | Texas | 20000 5 | David | 27 | Texas | 20000 6 | Kim | 22 | Texas | 20000 7 | James | 24 | Texas | 20000 3 | Teddy | 23 | Texas | 20000 (7 rows)