MySQL查询篇-集合运算

文章目录

• [union （并集）](#union （并集）)
• • [union distinct](#union distinct)
  • [union all](#union all)
• intersect(交集)
• • [intersect all](#intersect all)
  • [intersect distinct](#intersect distinct)
• [except 差集](#except 差集)
• • [except distinct](#except distinct)
  • [except distinct](#except distinct)
  • [except all](#except all)

union （并集）

union distinct

使用前提：a和c数据类型一致，b和d数据类型一致，查询的两个结果集列数也得相同

默认的union 即为union distinct

select a,b from table1
union
select c,d from table2;

union all

并集不去重

MySQL只支持union

intersect(交集)

intersect all

intersect distinct

except 差集

except distinct

except 差集

except distinct

except all