根据其他列值进行条件替换

您可以尝试以下查询:

SELECT
    CASE WHEN Code IS NULL
         THEN FileName
         ELSE REPLACE(FileName, Code + ' - ', 'xxxx - ') END AS label
FROM yourTable;

Demo

你不一定需要 WHERE 子句,因为替换逻辑已经检查是否存在匹配项。注意,我搜索 code - ,即您所期望的上下文中的代码。这至少部分缓解了出现虚假替代品的可能性。

试试这个

CREATE TABLE #tmp (Code varchar(25), FileName varchar (25))

INSERT INTO #tmp VALUES
(NULL, 'Cats and Dogs '),
('C123', 'C123 - Cats and Dogs'),
(NULL, 'Baking Cakes'),
('Z345', 'Z345 - Plants'),
('F967', 'E345 - Tractors')

SELECT  
CASE 
      WHEN CHARINDEX(Code, FileName,1)>0 THEN Replace(FileName, Code, 'xxxx') 
      ELSE FileName 
END As Result
FROM #tmp