MySQL 如何模拟带有WHERE子句的MySQL INTERSECT查询？

由于我们无法在MySQL中使用INTERSECT查询，因此我们将使用IN运算符来模拟INTERSECT查询。可以通过以下示例理解。

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例子

在此示例中，我们有两个表，分别为Student_detail和Student_info，其中包含以下数据。

mysql> Select * from Student_detail;
+-----------+---------+------------+------------+
| studentid | Name    | Address    | Subject    |
+-----------+---------+------------+------------+
|       101 | YashPal | Amritsar   | History    |
|       105 | Gaurav  | Chandigarh | Literature |
|       130 | Ram     | Jhansi     | Computers  |
|       132 | Shyam   | Chandigarh | Economics  |
|       133 | Mohan   | Delhi      | Computers  |
|       150 | Rajesh  | Jaipur     | Yoga       |
|       160 | Pradeep | Kochi      | Hindi      |
+-----------+---------+------------+------------+
7 rows in set (0.00 sec)

mysql> Select * from Student_info;
+-----------+-----------+------------+-------------+
| studentid | Name      | Address    | Subject     |
+-----------+-----------+------------+-------------+
|       101 | YashPal   | Amritsar   | History     |
|       105 | Gaurav    | Chandigarh | Literature  |
|       130 | Ram       | Jhansi     | Computers   |
|       132 | Shyam     | Chandigarh | Economics   |
|       133 | Mohan     | Delhi      | Computers   |
|       165 | Abhimanyu | Calcutta   | Electronics |
+-----------+-----------+------------+-------------+
6 rows in set (0.00 sec)

现在，下面的查询使用带有WHERE子句的IN运算符来模拟INTERSECT，以返回在两个表中都存在的大于130的“studentid”值。

mysql> Select Student_detail.studentid FROM Student_detail WHERE student_detail.studentid >130 AND student_detail.studentid IN(SELECT Student_info.studentid FROM Student_info WHERE Student_detail.studentid > 0);
+-----------+
| studentid |
+-----------+
|       132 |
|       133 |
+-----------+
2 rows in set (0.00 sec)