去除指定表中数据类型是VARCHAR,CHAR,NVARCHAR的字段值中的不可见字符

--作用：去除指定表中数据类型是VARCHAR,CHAR,NVARCHAR的字段值中的不可见字符
--注意：此处只去掉前后的不可见字符，不包括中间的字符，而且没有区分中文
--有兴趣的可以自己加个判别的中文，其实也很简单的，就是限定一个字符的范围就可以了
--日期：2004－11－04
--作者：ICERIVER
--注意：使用前请指定对应要修改的表名，并且需要在对应数据库下执行；
SET NOCOUNT ON
DECLARE @TblName VARCHAR(100)
DECLARE @UpdateString NVARCHAR(1000)
DECLARE @SelectString NVARCHAR(1000)
DECLARE @COlName VARCHAR(100)
DECLARE @COUNT INT
SET @TblName = 'YOURTABLENAME'--指定想要修改的表名
--定义游标取出指定表内的数据类型是VARCHAR,char,nVARCHAR的字段名称
DECLARE cur_ColName CURSOR
FOR
SELECT col.name
FROM syscolumns AS col
 inner join sysobjects AS obj ON col.ID = obj.ID
 INNER join systypes AS typ ON col.xtype = typ.xtype
WHERE obj.xtype ='U'
AND obj.name = @TblName
AND typ.name IN ('VARCHAR','CHAR','NVARCHAR','NCHAR')
FOR READ ONLY
--打开游标
OPEN cur_ColName
FETCH NEXT FROM cur_ColName INTO @ColName
IF @@FETCH_STATUS<>0
BEGIN
 PRINT '没有对应表或字段，'
 PRINT '请确认当前数据库内有' + @TblName + '表，'
 PRINT '或该表内有VARCHAR、CHAR、NVARCHAR、NCHAR类型的字段！'
 GOTO LABCLOSE
END
--循环修改
WHILE @@FETCH_STATUS=0
BEGIN
 --拼修改字符串
 --去掉左边的不可见字符
 SET @SelectString = 'SELECT @COU=COUNT(*)
 FROM ' + @TblName +'
 WHERE ASCII(LEFT(' + @ColName +',1))<32
 AND '+ @ColName + ' IS NOT NULL'
EXEC sp_executesql @SelectString,N'@COU INT OUTPUT',@COUNT OUTPUT
WHILE @COUNT>0
 BEGIN
 SET @UpdateString =
 ' UPDATE ' + @TblName +
 ' SET ' + @ColName + '=RIGHT(' + @ColName + ',LEN(' + @ColName + ')-1)
 WHERE ASCII(LEFT(' + @ColName + ',1))<32
 AND ' + @ColName + ' IS NOT NULL'
EXEC sp_executesql @UpdateString
 EXEC sp_executesql @SelectString,N'@COU INT OUTPUT',@COUNT OUTPUT
 END
--去掉右边的不可见字符
 SET @SelectString = 'SELECT @COU=COUNT(*)
 FROM ' + @TblName +'
 WHERE ASCII(RIGHT(' + @ColName +',1))<32
 AND '+ @ColName + ' IS NOT NULL'
EXEC sp_executesql @SelectString,N'@COU INT OUTPUT',@COUNT OUTPUT
WHILE @COUNT>0
 BEGIN
 SET @UpdateString =
 ' UPDATE ' + @TblName +
 ' SET ' + @ColName + '=LEFT(' + @ColName + ',LEN(' + @ColName + ')-1)
 WHERE ASCII(RIGHT(' + @ColName + ',1))<32
 AND ' + @ColName + ' IS NOT NULL'
EXEC SP_EXECUTESQL @UpdateString
 EXEC sp_executesql @SelectString,N'@COU INT OUTPUT',@COUNT OUTPUT
 END
PRINT 'column: ' + @ColName + '－－－ok'
 FETCH NEXT FROM cur_ColName INTO @ColName
END
--关闭、释放游标
LABCLOSE: CLOSE cur_ColName
 DEALLOCATE cur_ColName

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