只有第一個字母在SQL Server上更新

Question

我試圖在我的應用程序上合併兩個命令...我聲明瞭兩個變量來更新它們...例如，訂單有一個服務員（約翰）和一個表數（21）......我想用相同的服務員和表更新二階..所以我讓服務員爲（J）和表作爲（2）

這是我的查詢

declare @orderOne float = 4429 ; 
declare @orderTwo float = 4893 ; 
declare @tableNumber varchar = (SELECT TOP 1 tableNumber FROM ORDERS WHERE orderId in (@orderOne,@orderTwo) AND isActive = 0); 
declare @waiterN varchar = (SELECT TOP 1 waiterName FROM ORDERS WHERE orderId in (@orderOne,@orderTwo) AND isActive = 0); 

UPDATE orders SET orderId = @orderOne , tableNumber = @tableNumber , waiterName = @waiterN where orderId = @orderTwo ; 

Answer 1

declare @orderOne float = 4429 ; 
declare @orderTwo float = 4893 ; 
declare @tableNumber varchar(100); --<-- define variable length, default is 1 
declare @waiterN varchar(100);  --<-- define variable length, default is 1 

SELECT TOP 1 @tableNumber = tableNumber 
      ,@waiterN = waiterName 
FROM ORDERS WHERE orderId in (@orderOne,@orderTwo) AND isActive = 0; 



UPDATE orders 
    SET orderId = @orderOne 
    , tableNumber = @tableNumber 
    , waiterName = @waiterN 
where orderId = @orderTwo ;