在MySQL中，我們可以利用交集、并集、差集等命令來實現對多個數據集的相交、合并、差分等操作。
下面分別介紹這三種命令的用法：

交集命令：intersect

intersect，即求多個數據集的交集。用法如下:

SELECT column_name(s) FROM table1 
INTERSECT 
SELECT column_name(s) FROM table2;

示例：

SELECT * FROM table1 WHERE column_name IN 
(SELECT column_name FROM table2);

并集命令：union

union，即求多個數據集的并集。用法如下：

SELECT column_name(s) FROM table1 
UNION 
SELECT column_name(s) FROM table2;

示例：

SELECT * FROM table1 
WHERE column_name NOT IN (SELECT column_name FROM table2) 
UNION ALL 
SELECT * FROM table2;

差集命令：except

except，即求多個數據集的差集。用法如下：

SELECT column_name(s) FROM table1 
EXCEPT 
SELECT column_name(s) FROM table2;

示例：

SELECT * FROM table1 WHERE column_name 
NOT IN (SELECT column_name FROM table2);