如何創建一個函數以便從if語句返回一個字符？

Question

我有一個名爲EmployeeTransfers的表EmpIdSSN，EmpBasePay，EmpTransferState和EmpFederalFilingStatus表。我創建的函數需要兩個參數，它們是狀態和歸檔狀態，因此它應該通過if語句並返回該代碼來確定代碼是什麼。我此刻的錯誤如下：

消息444，級別16，狀態2，過程GetStateFilingStatus，6號線[批量起始行62]包含一個函數內不能將數據返回到客戶端Select語句。

我還遇到的其他問題是我想捕獲所有其他未包含在if語句中的狀態，以發送單一的通用代碼'S'和已婚的'M'。我試圖在最後做一個else語句，但不斷遇到各種錯誤。

create table EmployeeTransfers 
(
     EmpIdSSN char(9), 
     EmpBasePay decimal(16,4), 
     EmpTransferState char(2), 
     EmpFederalFilingStatus char(1) 
) 
GO 

--Input data 
insert into EmployeeTransfers 
values 
('555342121',60000.00, 'CA', 'S'), 
('552342120',70000.00, 'NY', 'M'), 
('552342120',87000.00, 'AZ', 'M'), 
('456772332',55000.00, 'CT', 'S'), 
('332223445',33000.00, 'NJ', 'M'), 
('550667788',54000.00, 'DC', 'M') 
GO 

create function dbo.GetStateFilingStatus(@EmpFederalFilingStatus char(1), @EmpTransferState char(2)) 
returns char(1) 
as 
begin 
    declare @StateFilingStatus char; 
    select @StateFilingStatus 
    from EmployeeTransfers 
    where EmpFederalFilingStatus = @EmpFederalFilingStatus 
     and EmpTransferState = @EmpTransferState; 
    if (@EmpTransferState = 'MS') and (@EmpFederalFilingStatus = 'S') 
     set @StateFilingStatus = 'A'; 
     else 
     set @StateFilingStatus = 'M'; 
    return @StateFilingStatus; 
    if (@EmpTransferState = 'NJ') and (@EmpFederalFilingStatus = 'S') 
     set @StateFilingStatus = 'B'; 
     else 
     set @StateFilingStatus = 'A'; 
    return @StateFilingStatus; 
    if (@EmpTransferState = 'AZ') and (@EmpFederalFilingStatus = 'S') 
     set @StateFilingStatus = 'A'; 
     else 
     set @StateFilingStatus = 'B'; 
    return @StateFilingStatus; 
    if (@EmpTransferState = 'CT') and (@EmpFederalFilingStatus = 'S') 
     set @StateFilingStatus = 'F'; 
     else 
     set @StateFilingStatus = 'M'; 
    return @StateFilingStatus; 
    if (@EmpTransferState = 'DC') and (@EmpFederalFilingStatus = 'S') 
     set @StateFilingStatus = 'S'; 
     else 
     set @StateFilingStatus = 'Y'; 
    return @StateFilingStatus; 
end; 
go 

Answer 1

我猜測你想要什麼是：

create function dbo.GetStateFilingStatus(@EmpFederalFilingStatus char(1), @EmpTransferState char(2)) 
returns char(1) 
as 
begin 
    declare @StateFilingStatus char; 
    if (@EmpTransferState = 'MS') 
    begin 
     if (@EmpFederalFilingStatus = 'S') 
      set @StateFilingStatus = 'A'; 
     else 
      set @StateFilingStatus = 'M'; 
    end 
    else 
    if (@EmpTransferState = 'NJ') 
    begin 
     if (@EmpFederalFilingStatus = 'S') 
      set @StateFilingStatus = 'B'; 
     else 
      set @StateFilingStatus = 'A'; 
    end 
    else 
    if (@EmpTransferState = 'AZ') 
    begin 
     if (@EmpFederalFilingStatus = 'S') 
      set @StateFilingStatus = 'A'; 
     else 
      set @StateFilingStatus = 'B'; 
    end 
    else 
    if (@EmpTransferState = 'CT') 
    begin 
     if (@EmpFederalFilingStatus = 'S') 
      set @StateFilingStatus = 'F'; 
     else 
      set @StateFilingStatus = 'M'; 
    end 
    else 
    if (@EmpTransferState = 'DC') 
    begin 
     if (@EmpFederalFilingStatus = 'S') 
      set @StateFilingStatus = 'S'; 
     else 
      set @StateFilingStatus = 'Y'; 
    end 
    else 
    begin -- this is your catch-all condition for all other States 
     -- you will probably need to modify this because I don't know 
     -- what your criteria are for returning 'S' or 'M' 
     if (@EmpFederalFilingStatus = 'S') 
      set @StateFilingStatus = 'S'; 
     else 
      set @StateFilingStatus = 'M'; 
    end 
    return @StateFilingStatus 
end; 
go