【TSQL】空格的比较

空格比较时 空字符串跟任意长度的半角空格字符串比较，结果都为TRUE

DECLARE @TRUSTOR VARCHAR(5)
SET @TRUSTOR = ''

IF @TRUSTOR IS NULL
  BEGIN
    SELECT 'IS NULL'
  END
IF @TRUSTOR = SPACE(5)
  BEGIN
    SELECT ''''' = SPACE5'
  END

-- 执行结果：'' = SPA