Question

我有两张结构相同的桌子。 Table1保留审核数据，table2保留其余数据。

表1

+------+--------+---------------+--------+-----------+
| "id" | "name" | "description" | "type" | "country" |
+------+--------+---------------+--------+-----------+
| "1"  | "a"    | "x"           | "1"    | "US"      |
| "2"  | "b"    | "x"           | "1"    | "UK"      |
+------+--------+---------------+--------+-----------+

表2

+------+-----------+-----------------+--------+-----------+----------+
| "id" |  "name"   |  "description"  | "type" | "country" | "status" |
+------+-----------+-----------------+--------+-----------+----------+
| "1"  | "Title 1" | "Description 1" | "1"    | "US"      | "0"      |
| "2"  | "Title 2" | "Description 2" | "10"   | "UK"      | "0"      |
+------+-----------+-----------------+--------+-----------+----------+

我运行下面的sql以使用来自table 1的数据更新table 2，并且效果很好。唯一的问题是，我需要在两个地方指定id。如果我只在一个地方指定它，它会去哪里？

UPDATE table1 dest, 
       (SELECT name, 
               description 
        FROM   table2 
        WHERE  id = 1) src 
SET    dest.name = src.name, 
       dest.description = src.description 
WHERE  dest.id = 1;

这件事的方式是：

UPDATE table1 SET name AND description =
(
   SELECT name, description from table2
   WHERE id=1 AND country=us and type=10
) WHERE id=idfromselect AND country=countryfromselect AND type=typefromselect

我无法确定id和remaining conditions的放置位置。你能帮忙吗？

Answer 1

将它作为连接，将id放在连接条件中，只检查WHERE子句中的id。

这样的事情： -

UPDATE table1 dest INNER JOIN table2 src ON dest.id = src=id
SET dest.name = src.name, dest.description = src.description 
WHERE dest.id=1 ;

任何其他限制都可以添加到WHERE子句

Answer 2

我认为您可以使用INNER JOIN查询根据table2中的数据更新您的table1，并将您的条件放在WHERE子句中

UPDATE table1 a
INNER JOIN table2 b
ON a.id = b.id
SET a.name = b.name,
a.description = b.description
WHERE a.id=1;

MySql使用另一个表中的数据更新表

2 个答案: