MYSQL使用不当兰德

Question

我试图与JOIN更新和RAND

UPDATE table1 a INNER JOIN table2 b USING(id) 
SET a.description = CONCAT('different words', b.name) 
WHERE a.description LIKE '' 
ORDER BY RAND() LIMIT 100; 

我得到的错误：UPDATE和秩序的不正确的使用情况

无连接下面的代码工作完美

UPDATE table1 SET description = CONCAT('different words', name) 
WHERE description LIKE '' 
ORDER BY RAND() LIMIT 100; 

感谢帮助

Answer 1

假设你正在使用mysql，你应该把你的查询（用户变量和顺序）作为内联视图（MySQL称之为派生表）来包装。将整个视图作为UPDATE语句中的行源引用。所以，你的查询应该是这样的：

UPDATE table1 a 

INNER JOIN ( 
     --query 
     ) as someName 
SET a.description = CONCAT('different words', b.name) 

Answer 2

试试这个：

UPDATE a 
SET a.description = CONCAT('different words', b.name) 
FROM table1 a 
INNER JOIN table2 b ON a.id=b.id 
WHERE a.description LIKE '' 
ORDER BY RAND() LIMIT 100;