2 在 1 个插入中选择语句

Question

Insert into sold(invId, cusId, LCnumfk, Name, Category, Brand, Price, ExDate, Tags, Quantity, Barcode)   
Select I.Id, L.Id, L.LCnum, I.Name, I.Category, I.Brand, I.Price, I.ExDate, I.Tags, I.Quantity, I.Barcode from inventory as I   
INNER JOIN sold as S on I.Id = S.invId INNER JOIN loyaltycard as L on S.CusId = L.Id where I.Barcode = 356554745

首先，我有一个名为 inventory、sold 和会员卡的表。表库存由列名称、类别、品牌、价格...组成，忠诚卡的列名称为 id 和 LCnum。我希望将所有这些值插入到已售表中。我该怎么做？

我尝试了这段代码并尝试了运气，但仍然没有..

Insert into sold(invID, Name, Category, Brand, Price, ExDate, Tags, Quantity, Barcode)  
Select Id, Name, Category, Brand, Price, ExDate, Tags, Quantity, Barcode from inventory  
where Barcode = '3565547456644' 
Insert into sold(CusId, LCnumfk)   
Select Id, LCnum from loyaltycard where LCnum = '347'

这是数据库的结构：

inventory(Id int , Name varchar(255), Category varchar(255), Brand varchar(255), Price int, ExDate date, Tags varchar(255), Quantity int, Barcode varchar(255))

sold(invId int, CusId int, LCnumfk int,Name varchar(255), Category varchar(255), Brand varchar(255), Price int, ExDate date, Tags varchar(255), Quantity int, Barcode varchar(255) ) 

loyaltycard(Id int, LCnum int)

sold foreign key LCnumfk has a constraint to loyaltycard LCnum

sold invId is a foreign key and has a constraint to inventory Id 

Answer 1

如果您执行 2 次插入 - 第一组的 CustId 和 LCnumfk 将为 NULL。第二个插入语句会将除 CustId 和 LCnumfk 之外的所有其他字段填充为 NULL。

这会导致无效数据。

需要做什么-

第 1 步 - 插入数据

Insert into sold(invID, Name, Category, Brand, Price, ExDate, Tags, Quantity, Barcode)  
Select Id, Name, Category, Brand, Price, ExDate, Tags, Quantity, Barcode from inventory  
where Barcode = '3565547456644' 

第 2 步 - 更新第 1 步中插入的“已售”表的行

Update sold
SET CusId = (Select Id from loyaltycard where LCnum = '347'),
LCnumfk = (Select LCnum from loyaltycard where LCnum = '347')

尽管您应该用连接替换子查询以正确更新所有行。