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内联接在SQL92中 ON 暗示联接添加，可选的WHERE子句暗示过滤前提，如开篇的示例就是一个多表的内联接，我们在看一个简朴的示例: 查询后果大于80分的门生学号，门生姓名和后果:
- mysql> SELECT
- -> stu.no, stu.name , s.score
- -> FROM student stu JOIN score s ON sstu.no = s.s_no
- -> WHERE s.score > 80;
- +------+-------+-------+
- | no | name | score |
- +------+-------+-------+
- | S001 | Sunny | 98 |
- | S003 | Kevin | 88 |
- +------+-------+-------+
- 2 rows in set (0.00 sec)
上面按语义的逻辑是:
- 第一步：先举办student和score的内毗连，如下：
- mysql> SELECT
- -> stu.no, stu.name , s.score
- -> FROM student stu JOIN score s ON sstu.no = s.s_no ;
- +------+-------+-------+
- | no | name | score |
- +------+-------+-------+
- | S001 | Sunny | 80 |
- | S001 | Sunny | 98 |
- | S001 | Sunny | 76 |
- | S003 | Kevin | 78 |
- | S003 | Kevin | 88 |
- | S003 | Kevin | 68 |
- +------+-------+-------+
- 6 rows in set (0.00 sec)
第二步：对内联功效举办过滤， score > 80 获得，如下最终功效：
- -> WHERE s.score > 80;
- +------+-------+-------+
- | no | name | score |
- +------+-------+-------+
- | S001 | Sunny | 98 |
- | S003 | Kevin | 88 |
- +------+-------+-------+
- 2 rows in set (0.00 sec)
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