Question

更新一个表，再加一个表。

UPDATE t1 SET  t1.col1 =1 FROM table1 t1 JOIN  table2 t2 
ON t1.ID=t2.ID
WHERE t1.Name='Test' AND t2.Age=25;

我收到此错误，您的SQL语法出错;查看与您的MySQL服务器版本对应的手册，以便在'FROM table1 t1 JOIN table2 t2 ...

附近使用正确的语法

有什么想法吗？

感谢。

Answer 1

UPDATE语句中不应该有FROM子句，SET子句应该遵循完整的表引用集：

UPDATE  table1 t1 
JOIN    table2 t2 ON t1.ID = t2.ID
SET     t1.col1 = 1
WHERE   t1.Name = 'Test' AND t2.Age = 25;

测试用例：

CREATE TABLE table1 (id int, col1 int, name varchar(20));
CREATE TABLE table2 (id int, age int);

INSERT INTO table1 VALUES (1, 0, 'Test');
INSERT INTO table1 VALUES (2, 0, 'Test');
INSERT INTO table1 VALUES (3, 0, 'No Test');

INSERT INTO table2 VALUES (1, 20);
INSERT INTO table2 VALUES (2, 25);
INSERT INTO table2 VALUES (3, 25);

结果：

SELECT * FROM table1;
+------+------+---------+
| id   | col1 | name    |
+------+------+---------+
|    1 |    0 | Test    |
|    2 |    1 | Test    |
|    3 |    0 | No Test |
+------+------+---------+
3 rows in set (0.00 sec)

Answer 2

UPDATE  table1 SET  col1 = 1
from table1 t1
JOIN    table2 t2 ON t1.ID = t2.ID
WHERE   t1.Name = 'Test' AND t2.Age = 25;

Answer 3

我在更新加入时遇到问题。在table1中我保存了用户名而不是userid。对于用户名数据类型是varchar（10）。当名称超过10时，名称仅保存10个字符。现在，当我尝试使用连接查询进行更新时，它不适用于那些在users表中没有完全unername的字段，请注意table1中的名称bill gat，但用户字段中的名称是bill gate - 缺少。

    UPDATE table1 AS tr
JOIN users AS u ON u.name LIKE CONCAT('%', tr.created_by, '%')
SET tr.created_by=u.id
WHERE tr.created_by IS NOT NULL

===我这样解决了

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更新连接另一个表的表

3 个答案: