#關於子查詢

有時候查詢條件來自其他where條件查詢出來的結果,這時候就要用兩個select去組合這個結果

1.查詢這個team_id裡面又要找尋win的場數大於23⇒結果 team_id =6及4

SELECT * FROM sampledatabase.sbl_team_data where team_id in (SELECT team_id  FROM sampledatabase.sbl_team_data where win > 23);

2.查詢特定資料例如team_id=7且存在於sbl_team_data.team_id

SELECT * FROM sampledatabase.sbl_team_data where team_id =7 and exists
(SELECT * FROM sampledatabase.sbl_team_data where sbl_team_data.team_id );

#DB-Transation