Question

我有一个看起来像这样的表：

+----+--------+-------+
| id | entity | word  |
+----+--------+-------+
|  1 |      1 | red   |
|  2 |      1 | green |
|  3 |      1 | blue  |
|  4 |      2 | car   |
|  5 |      2 | truck |
|  6 |      2 | train |
|  7 |      3 | water |
|  8 |      3 | milk  |
|  9 |      3 | soda  |
+----+--------+-------+

如果我搜索blue，我希望red，green和blue作为答案。现在我正在使用2个查询。一个用于查找“实体”编号，另一个用于查找具有相同“实体”编号的所有单词。

Answer 1

试试这个。加入比子查询快得多

select distinct t2.word from Table t1 
INNER JOIN Table t2 on t2.entity=t1.entity
where t1.word="blue";

Answer 2

SELECT *
FROM TABLE_NAME
WHERE entity IN
    (SELECT entity
     FROM TABLE_NAME
     WHERE word='blue');

简化MySQL查询 - 将2个查询转换为1

2 个答案: