sql len函数 CASE WHEN
SELECT LEN('SQL Server LEN') length, LEN('SQL Server LEN ') length_with_trailing_blanks; SELECT (CASE WHEN LEN('')=0 THEN '001' ELSE '1线' END) --执行001 SELECT (CASE WHEN LEN('1线')=0 THEN '001' ELSE '1线' END) --执行1线 来源: https://www.cnblogs.com/enych/p/11589416.html