UNION指令

• UNION用來把兩個查詢的答案做聯集
• 使用UNION必須是兩個查詢的欄位數量與型態一致

select name from main where sex='女性'

union

select name from main where name like '陳%';

• 可以用第一個Query的欄位來order by
• select name from main where sex='女'

union

select name from main where name like '陳%' order by name desc