问题描述
select name, phone, 'users' as table_name from users
union
select name, phone, 'vendors' as table_name from vendors;
更好的解决方案是使用union all，因此服务器将不会检查不同的值
select name, phone, 'users' as table_name from users
union all
select name, phone, 'vendors' as table_name from vendors;
解决方法
如果我有一个简单的工会
select name,phone from users union select name,phone from vendors;
有没有一种方法可以将表名添加到结果中？
所以代替
+--------+-------+
| name | phone |
+--------+-------+
| Jim | 123...|
| Macy's | 345...|
+--------+-------+
我会
+--------+-------+---------+
| name | phone | table |
+--------+-------+---------+
| Jim | 123...| users |
| Macy's | 345...| vendors |
+--------+-------+---------+