我的数据库中有两个表。我想从一个表中选择record，如果其他表不是那个记录

I have two table "A" and "B". I want to select record from table "A" only if "B" table not that requested values according to given ID. In my code I pass my "ID" to select record. I want to select record from "A" table if only "B" table doesn't exist requested record.

我有两张桌子“A”和“B”。我想要从表A中选择record，只当B表中没有根据给定ID请求的值。在我的代码中，我将我的ID传递给select record。我想要从“A”表中选择record，如果只有“B”表不存在则请求记录。

1 个解决方案

#1

You can pretty much put that into SQL words

你可以把它放到SQL语句中。

SELECT * 
FROM TABLE A
WHERE A.ID = ? 
AND A.ID NOT IN (
    SELECT B.ID 
    FROM TABLE B
    WHERE B.ID = ?
)

Use the ? as placeholder with a PreparedStatement (safe) or replace them manually with the value you want (unsafe).

使用?使用PreparedStatement (safe)作为占位符，或者使用您想要的值(不安全)手动替换它们。

#1