将数据类型转换为 case 语句的文本

Question

I need to convert data type to text for following statement. Can someone please help…

CASE WHEN [OrderID] IS NULL THEN 'N'
     WHEN [Order_ID] = '' THEN 'N'
     ELSE [Order_ID] END AS [Order_ID]

Answer 1

Try casting the order ID to varchar in the ELSE branch of your CASE expression:

CASE WHEN COALESCE([Order_ID], '') = ''
     THEN 'N'
     ELSE CAST([Order_ID] AS VARCHAR(MAX)) END AS [Order_ID]

Answer 2

consider isnull()

CASE WHEN isnull([OrderID], '') = '' THEN 'N'   
     ELSE cast([Order_ID] as varchar(300)) END AS [Order_ID]

Answer 3

Try this Alternate Method-

IIF(ISNULL([OrderID],'')='','N',CAST([OrderID] AS NVARCHAR(MAX))) AS [OrderID]

Answer 4

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You Can try below also:

CASE WHEN OrderID IS NULL THEN 'N'
          WHEN OrderID  ='' THEN 'N'
          ELSE convert(varchar(20),OrderID ) END