Postgresql 简明教程

PostgreSQL - UPDATE Query

PostgreSQL UPDATE 查询用于修改表中的现有记录。您可以将 WHERE 子句与 UPDATE 查询一起使用以更新选定的行。否则，所有行都将被更新。

The PostgreSQL UPDATE Query is used to modify the existing records in a table. You can use WHERE clause with UPDATE query to update the selected rows. Otherwise, all the rows would be updated.

Syntax

带 WHERE 子句的 UPDATE 查询的基本语法如下 −

The basic syntax of UPDATE query with WHERE clause is as follows −

UPDATE table_name
SET column1 = value1, column2 = value2...., columnN = valueN
WHERE [condition];

可以使用 AND 或 OR 运算符组合 N 个条件。

You can combine N number of conditions using AND or OR operators.

Example

考虑表 COMPANY ，具有如下记录 −

Consider the table COMPANY, having records as follows −

testdb# 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)

下面是一个示例，此示例将更新 ID 为 6 的客户的 ADDRESS −

The following is an example, which would update ADDRESS for a customer, whose ID is 6 −

testdb=# UPDATE COMPANY SET SALARY = 15000 WHERE ID = 3;

现在，COMPANY 表将具有以下记录 −

Now, COMPANY table would have the following records −

 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
(7 rows)

如果您想在 COMPANY 表中修改所有 ADDRESS 和 SALARY 列值，不需要使用 WHERE 子句，并且 UPDATE 查询如下所示 −

If you want to modify all ADDRESS and SALARY column values in COMPANY table, you do not need to use WHERE clause and UPDATE query would be as follows −

testdb=# UPDATE COMPANY SET ADDRESS = 'Texas', SALARY=20000;

现在，COMPANY 表将包含以下记录 −

Now, COMPANY table will have the following records −

 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)