Practical practice of mysql sentence writing (combining left company with subquery)
Select
C.card_number
C.card_name
T.type_name
C.card_discount
T.type_low
C.card_integral
(c.card_recharge_balance+c.card_give_balance) as num
V.people
C.card_time
From
`vip_ Card` as c
Left join
(
Select
Count (vipid) as people
Card_number
From vip
Group by card_number
) as v
On
C.card_number=v.card_number
Left join
`vip_ type` as t
On
C.type_id=t.type_id
Where
C. Storekeeper keyword 556655'
