查询关系表

Question

我有这个数据的关系表。我想要的是一个返回a_id的查询，每个连接的status等于1。

所以在这种情况下，6将是返回的值。

a_id b_id status
4     757   0
4     758   0
4     761   0
5     757   1
5     758   0
5     761   1
6     757   1
6     761   1
6     758   1

MySQL 5.5

Answer 1

SELECT DISTINCT a_id
FROM relation_table
WHERE a_id NOT IN (SELECT a_id FROM relation_table WHERE status != 1);

Answer 2

试试这个

SELECT DISTINCT a_id
FROM table1
WHERE a_id NOT IN
    (SELECT a_id
     FROM table1
     WHERE status != 1);

SQL Fiddle

Answer 3

SELECT DISTINCT a_id FROM table_name WHERE a_id NOT IN（SELECT a_id FROM table_name WHERE status = 0）;

参考： http://www.w3schools.com/sql/trysql.asp?filename=trysql_select_distinct