條件SQL查詢Ç

Question

我

tbl_ticket_categories(id , category_name , description , site_referers_id)

tbl_ticket_repliers(id , user_id , category_id , site_referers_id)

tbl_users(id , role_id , username , password)

我想選擇tbl_ticket_categories所有category_name和description其中site_referers_id = 1

，以及那些username其user_id位於tbl_ticket_repliers。

Answer 1

SELECT category_name, description, tu.username 
    FROM tbl_ticket_categories tc 
    INNER JOIN tbl_ticket_repliers tr 
     ON tc.id = tr.category_id 
    INNER JOIN tbl_users tu 
     ON tr.user_id = tu.id 
    WHERE tc.site_referers_id = 1 

See this fiddle

Answer 2

select category_name,description,username from tbl_ticket_categories as ttc 
join tbl_ticket_repliers as ttr on ttr.category_id=ttc.id 
join tbl_users as tu on tu.id=ttc.user_id 
where site_referers_id = 1 

這是你得到確切的結果中查詢檢查一次