我遇到了同样的问题,并确定出现此问题是因为 SQL Server 没有对以相同方式转换为整数的字符执行比较。在我的测试中,我发现有些转换字符的比较,比如感叹号,会返回类型转换错误,而其他转换字符的比较,比如空格,会被判断为超出范围。
此示例代码测试了不同的可能场景,并使用嵌套的 REPLACE 语句提供了解决方案。 REPLACE 判断字符串中是否有非数字或斜线的字符,如果存在,则字符串的长度将大于零,从而表明存在“坏”字符且日期无效.
DECLARE @str varchar(10)
SET @str = '12/10/2012'
IF convert(int, substring(@str,4,2)) <= 31 AND convert(int, substring(@str,4,2)) >= 1
PRINT @str+': Passed Test'
ELSE PRINT @str+': Failed Test'
GO
DECLARE @str varchar(10)
SET @str = '12/10/2012'
PRINT 'Number of characters in ' + @str + ' that are not numerals or a slash (0 means the date is valid; all values greater than 0 indicate a problem): ' + convert(varchar(5),len(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(@str,'0',''),'1',''),'2',''),'3',''),'4',''),'5',''),'6',''),'7',''), '8',''),'9',''),'/',''),' ','+'))) --replace space with a + to avoid empty string
PRINT ''
GO
DECLARE @str varchar(10)
SET @str = '12/!0/2012'
IF convert(int, substring(@str,4,2)) <= 31 AND convert(int, substring(@str,4,2)) >= 1
PRINT @str+': Passed Test'
ELSE PRINT @str+': Failed Test'
GO
DECLARE @str varchar(10)
SET @str = '12/!0/2012'
PRINT 'Number of characters in ' + @str + ' that are not numerals or a slash (0 means the date is valid; all values greater than 0 indicate a problem): ' + convert(varchar(5),len(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(@str,'0',''),'1',''),'2',''),'3',''),'4',''),'5',''),'6',''),'7',''), '8',''),'9',''),'/',''),' ','+'))) --replace space with a + to avoid empty string
PRINT ''
GO
DECLARE @str varchar(10)
SET @str = '12/ /2012'
IF convert(int, substring(@str,4,2)) <= 31 AND convert(int, substring(@str,4,2)) >= 1
PRINT @str+': Passed Test'
ELSE PRINT @str+': Failed Test'
GO
DECLARE @str varchar(10)
SET @str = '12/ /2012'
PRINT 'Number of characters in ' + @str + ' that are not numerals or a slash (0 means the date is valid; all values greater than 0 indicate a problem): ' + convert(varchar(5),len(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(replace(@str,'0',''),'1',''),'2',''),'3',''),'4',''),'5',''),'6',''),'7',''), '8',''),'9',''),'/',''),' ','+'))) --replace space with a + to avoid empty string
输出:
--Output
--12/10/2012: Passed Test
--Number of characters in 12/10/2012 that are not numerals or a slash (0 means the date is valid; all values greater than 0 indicate a problem): 0
--Msg 245, Level 16, State 1, Line 4
--Conversion failed when converting the varchar value '!0' to data type int.
--Number of characters in 12/!0/2012 that are not numerals or a slash (0 means the date is valid; all values greater than 0 indicate a problem): 1
--12/ /2012: Failed Test
--Number of characters in 12/ /2012 that are not numerals or a slash (0 means the date is valid; all values greater than 0 indicate a problem): 2