SQL 如何根据条件从 2 个表中获取数据

Question

我需要获取所有 id1，其中 id3 = 100

我试过了

SELECT id1 FROM "table 1" WHERE id2 = (SELECT id2 FROM "table 2" WHERE id3='100');

但 id2 的结果可能不止 1 个.. 所以当然我得到了一个错误

我怎样才能得到这些数据？？

Answer 1

SELECT id1 
FROM "table 1" 
WHERE id2 IN ( SELECT id2 
               FROM "table 2" 
               WHERE id3='100'
              );

Answer 2

如果我没看错的话，这里应该可以进行简单的连接：

SELECT t1.id1
FROM Table1 t1
INNER JOIN Table2 t2
    ON t2.id2 = t1.id2
WHERE t2.id3 = 100;

SQL how to get data from 2 tables with condition