sql - sql插入带有选择案例值的表

Question

出于某种原因，我对这个陈述有疑问

Insert into TblStuff
(FullName,Address,City,Zip)

Select
Case
When Middle is Null Then Fname + LName as FullName,
Else Fname +' ' + Middle + ' '+ Lname as FullName,
End
Case
When Address2 is Null Then Address1 as Address,
else Address1 +', ' + Address2 as  Address,
End
City as City,
Zip as Zip
from tblImport

我在关键字“as”附近收到不正确的语法

编辑添加到这个问题，让我知道是否需要添加新帖子。

我知道下面的陈述有点不同，但你能做一个类似于下面的案例陈述吗？下面的陈述甚至有意义吗？

Insert into TblStuff
    (NickName,FirstName,MiddleName,Suffix)

    Case when FirstName IS NULL then 
        NickName as Nickname,
        IsNULL(FirstName,'''') as FirstName,
        IsNULL(MiddelName,'''') as MiddleName,
        IsNULL(NameSuffix,'''') as Suffix,
    Else
        IsNull(NickName2,'''') as NickName,
        IsNULL(FirstName,'''') as FirstName,
        IsNULL(MiddelName,'''') as Middlename,
        Case when NameSuffix2 is NULL then
            IsNULL(NameSuffix,'''')as suffix,
        Else
            IsNULL(NameSuffix,'''') + '''', '''' + IsNULL(NameSuffix2,'''') as suffix,
        End
    End
From tblImport

Answer 1

end完成 case 语句后需要逗号。而且，“as”在case语句之后，而不是在它里面：

Insert into TblStuff(FullName, Address, City, Zip)
    Select (Case When Middle is Null Then Fname + LName
                 Else Fname +' ' + Middle + ' '+ Lname
            End)  as FullName,
           (Case When Address2 is Null Then Address1
                 else Address1 +', ' + Address2
            End)  as  Address,
           City as City,
           Zip as Zip
    from tblImport

Answer 2

您在案例内部有别名，它需要在以下内容之外END：

Insert into TblStuff (FullName,Address,City,Zip)
Select
  Case
    When Middle is Null 
    Then Fname + LName
    Else Fname +' ' + Middle + ' '+ Lname
  End as FullName,
  Case
    When Address2 is Null Then Address1
    else Address1 +', ' + Address2 
  End as  Address,
  City as City,
  Zip as Zip
from tblImport

Answer 3

您也可以使用COALESCE代替 CASE 表达式。因为将任何东西连接到 NULL 的结果，甚至它本身，总是 NULL

INSERT TblStuff(FullName,Address,City,Zip)
SELECT COALESCE(Fname + ' ' + Middle + ' ' + Lname, Fname + LName) AS FullName,
       COALESCE(Address1 + ', ' + Address2, Address1) AS Address, City, Zip
FROM tblImport

SQLFiddle上的演示

Answer 4

If FName and LName contain NULL values, then you will need special handling to avoid unnecessary extra preceeding, trailing, and middle spaces. Also, if Address1 contains NULL values, then you need to have special handling to prevent adding unnecessary ', ' at the beginning of your address string.

If you are using SQL Server 2012, then you can use CONCAT (NULLs are automatically treated as empty strings) and IIF:

INSERT INTO TblStuff (FullName, Address, City, Zip)
SELECT FullName = REPLACE(RTRIM(LTRIM(CONCAT(FName, ' ', Middle, ' ', LName))), '  ', ' ')
    , Address = CONCAT(Address1, IIF(Address2 IS NOT NULL, CONCAT(', ', Address2), ''))
    , City
    , Zip
FROM tblImport (NOLOCK);

Otherwise, this will work:

INSERT INTO TblStuff (FullName, Address, City, Zip)
SELECT FullName = REPLACE(RTRIM(LTRIM(ISNULL(FName, '') + ' ' + ISNULL(Middle, '') + ' ' + ISNULL(LName, ''))), '  ', ' ')
    , Address = ISNULL(Address1, '') + CASE
        WHEN Address2 IS NOT NULL THEN ', ' + Address2
        ELSE '' END
    , City
    , Zip
FROM tblImport (NOLOCK);