Question

我需要在表中插入值，但在检查完条件后请帮助我

提前致谢

insert into b (SELECT userID,username, ANSWERTOQUESTION1 AS AnswerToQuestion  From a 

UNION ALL 

SELECT userID,username, AnswerToQuestion2 AS aswertoquestion  From a)

我需要在b表中插入值，如果不存在的话。这意味着应该比较表中的所有值，以便我可以插入值

Answer 1

我的unserstanding，你想把记录插入B表中而不是B中的A表，所以最后B表将包含A中的所有值。

如果确实如此，

我希望以下内容有所帮助

Insert into B
Select userid, username, answertoquestion1 from a
minus
Select userid, username, answertoquestion1 from b;

由于 Thangamani Eraniyan

Answer 2

insert into b 
select t2.userID,t2.username,concat(t2.AnswerToQuestion1,t2.AnswerToQuestion2) 
from a as t2 
LEFT JOIN b t3 on t3.userID=t2.userID;

要避免重复记录，请使用以下查询：

INSERT INTO b 
SELECT t2.userID,t2.username,concat(t2.AnswerToQuestion1,t2.AnswerToQuestion2)  
FROM a AS t2 WHERE NOT EXISTS (SELECT * FROM b AS t3 WHERE t2.userID = t3.userID);

无法在SQL中插入带有检查条件的值

2 个答案: