微软SQL服务器INTERSECT http://msdn.microsoft.com/en-us/library/ms188055.aspx “返回由 INTERSECT 操作数左侧和右侧的查询返回的任何不同值”这与标准不同INNER JOIN
or WHERE EXISTS
query.
SQL服务器
CREATE TABLE table_a (
id INT PRIMARY KEY,
value VARCHAR(255)
);
CREATE TABLE table_b (
id INT PRIMARY KEY,
value VARCHAR(255)
);
INSERT INTO table_a VALUES (1, 'A'), (2, 'B'), (3, 'B');
INSERT INTO table_b VALUES (1, 'B');
SELECT value FROM table_a
INTERSECT
SELECT value FROM table_b
value
-----
B
(1 rows affected)
MySQL
CREATE TABLE `table_a` (
`id` INT NOT NULL AUTO_INCREMENT,
`value` varchar(255),
PRIMARY KEY (`id`)
) ENGINE=InnoDB;
CREATE TABLE `table_b` LIKE `table_a`;
INSERT INTO table_a VALUES (1, 'A'), (2, 'B'), (3, 'B');
INSERT INTO table_b VALUES (1, 'B');
SELECT value FROM table_a
INNER JOIN table_b
USING (value);
+-------+
| value |
+-------+
| B |
| B |
+-------+
2 rows in set (0.00 sec)
SELECT value FROM table_a
WHERE (value) IN
(SELECT value FROM table_b);
+-------+
| value |
+-------+
| B |
| B |
+-------+
对于这个特定问题,涉及到 id 列,因此不会返回重复值,但为了完整起见,这里有一个 MySQL 替代方案,使用INNER JOIN
and DISTINCT
:
SELECT DISTINCT value FROM table_a
INNER JOIN table_b
USING (value);
+-------+
| value |
+-------+
| B |
+-------+
另一个例子使用WHERE ... IN
and DISTINCT
:
SELECT DISTINCT value FROM table_a
WHERE (value) IN
(SELECT value FROM table_b);
+-------+
| value |
+-------+
| B |
+-------+