选择UNION ALL以将表名显示为附加列

Question

对于MSSQL或MySQL，这是一个将两个结果合二为一的查询：

SELECT boy as person from table1
union all
SELECT girl as person from table2

如何修改上面的查询，以便结果包含带有表名称的第二个（已添加）列（因此它包含table1或table2值。）

Answer 1

你可以给表格名称作为第二栏的字​​符串横向

SELECT boy as person, 'table1' as column2 from table1
union all
SELECT girl as person, 'table2' as column2 from table2

Answer 2

只需Hard code第二栏中的tablename

SELECT boy as person,'Table1' as Tablename from table1
UNION ALL
SELECT girl as person ,'Table2' as Tablename from table2

Answer 3

您需要将它们添加为文字：

SELECT boy as person, 'table1' as tablename from table1
UNION ALL
SELECT girl as person, 'table2' from table2