在日常應用中，往往根據實際需求錄入一些值，而這些值不能直接使用，所以Sql中經常會對字段值進行一些常規的處理。這里搜集了（提取數字、英文、中文、過濾重復字符、分割字符的方法），方便日后查詢使用。
一、判斷字段值是否有中文
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--SQL 判斷字段值是否有中文create function fun_getCN(@str nvarchar(4000)) returns nvarchar(4000) as begin declare @word nchar(1),@CN nvarchar(4000) set @CN='' while len(@str)>0 begin set @word=left(@str,1) if unicode(@word) between 19968 and 19968+20901 set @CN=@CN+@word set @str=right(@str,len(@str)-1) end return @CN endselect dbo.fun_getCN('ASDKG論壇KDL')--論壇select dbo.fun_getCN('ASDKG論壇KDL')--論壇select dbo.fun_getCN('ASDKDL')--空 |
二、提取數字
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IF OBJECT_ID('DBO.GET_NUMBER2') IS NOT NULLDROP FUNCTION DBO.GET_NUMBER2GOCREATE FUNCTION DBO.GET_NUMBER2(@S VARCHAR(100))RETURNS VARCHAR(100)ASBEGINWHILE PATINDEX('%[^0-9]%',@S) > 0BEGINset @s=stuff(@s,patindex('%[^0-9]%',@s),1,'')ENDRETURN @SENDGO--測試PRINT DBO.GET_NUMBER('呵呵ABC123ABC')GO--123 |
三、提取英文
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--提取英文IF OBJECT_ID('DBO.GET_STR') IS NOT NULLDROP FUNCTION DBO.GET_STRGOCREATE FUNCTION DBO.GET_STR(@S VARCHAR(100))RETURNS VARCHAR(100)ASBEGINWHILE PATINDEX('%[^a-z]%',@S) > 0BEGINset @s=stuff(@s,patindex('%[^a-z]%',@s),1,'')ENDRETURN @SENDGO--測試PRINT DBO.GET_STR('呵呵ABC123ABC')GO |
四、提取中文
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--提取中文IF OBJECT_ID('DBO.CHINA_STR') IS NOT NULLDROP FUNCTION DBO.CHINA_STRGOCREATE FUNCTION DBO.CHINA_STR(@S NVARCHAR(100))RETURNS VARCHAR(100)ASBEGINWHILE PATINDEX('%[^吖-座]%',@S) > 0SET @S = STUFF(@S,PATINDEX('%[^吖-座]%',@S),1,N'')RETURN @SENDGOPRINT DBO.CHINA_STR('呵呵ABC123ABC')GO |
五、過濾重復字段（多種方法）
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--過濾重復字符IF OBJECT_ID('DBO.DISTINCT_STR') IS NOT NULLDROP FUNCTION DBO.DISTINCT_STRGOCREATE FUNCTION DBO.DISTINCT_STR(@S NVARCHAR(100),@SPLIT VARCHAR(50))RETURNS VARCHAR(100)ASBEGINIF @S IS NULL RETURN(NULL)DECLARE @NEW VARCHAR(50),@INDEX INT,@TEMP VARCHAR(50)IF LEFT(@S,1)<>@SPLITSET @S = @SPLIT+@SIF RIGHT(@S,1)<>@SPLITSET @S = @S+@SPLITWHILE CHARINDEX(@SPLIT,@S)>0 AND LEN(@S)<>1BEGINSET @INDEX = CHARINDEX(@SPLIT,@S)SET @TEMP = LEFT(@S,CHARINDEX(@SPLIT,@S,@INDEX+LEN(@SPLIT)))IF @NEW IS NULLSET @NEW = ISNULL(@NEW,'')+@TEMPELSESET @NEW = ISNULL(@NEW,'')+REPLACE(@TEMP,@SPLIT,'')+@SPLITWHILE CHARINDEX(@TEMP,@S)>0BEGINSET @S=STUFF(@S,CHARINDEX(@TEMP,@S)+LEN(@SPLIT),CHARINDEX(@SPLIT,@S,CHARINDEX(@TEMP,@S)+LEN(@SPLIT))-CHARINDEX(@TEMP,@S),'')ENDENDRETURN RIGHT(LEFT(@NEW,LEN(@NEW)-1),LEN(LEFT(@NEW,LEN(@NEW)-1))-1)ENDGOPRINT DBO.DISTINCT_STR('A,A,B,C,C,B,C,',',')--A,B,CGO ----------------------------------------------------------------------過濾重復字符2IF OBJECT_ID('DBO.DISTINCT_STR2') IS NOT NULLDROP FUNCTION DBO.DISTINCT_STR2GOCREATE FUNCTION DBO.DISTINCT_STR2(@S varchar(8000))RETURNS VARCHAR(100)ASBEGINIF @S IS NULL RETURN(NULL)DECLARE @NEW VARCHAR(50),@INDEX INT,@TEMP VARCHAR(50)WHILE LEN(@S)>0BEGINSET @NEW=ISNULL(@NEW,'')+LEFT(@S,1)SET @S=REPLACE(@S,LEFT(@S,1),'')ENDRETURN @NEWENDGOSELECT DBO.DISTINCT_STR2('AABCCD')--ABCDGO |
六、根據特定字符串分割字段值
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IF OBJECT_ID('DBO.SPLIT_STR') IS NOT NULLDROP FUNCTION DBO.SPLIT_STRGOCREATE FUNCTION DBO.SPLIT_STR(@S varchar(8000), --包含多個數據項的字符串@INDEX int, --要獲取的數據項的位置@SPLIT varchar(10) --數據分隔符)RETURNS VARCHAR(100)ASBEGINIF @S IS NULL RETURN(NULL)DECLARE @SPLITLEN intSELECT @SPLITLEN=LEN(@SPLIT+'A')-2WHILE @INDEX>1 AND CHARINDEX(@SPLIT,@S+@SPLIT)>0SELECT @INDEX=@INDEX-1,@S=STUFF(@S,1,CHARINDEX(@SPLIT,@S+@SPLIT)+@SPLITLEN,'')RETURN(ISNULL(LEFT(@S,CHARINDEX(@SPLIT,@S+@SPLIT)-1),''))ENDGOPRINT DBO.SPLIT_STR('AA|BB|CC',2,'|')--GO |
