怎样在SQL Server中去除表中不可见字符

SQL Server数据库是很多人都在用的数据库管理系统，功能性很强大，以下的实例为去除指定表中数据类型VARCHAR,CHAR,NVARCHAR的字段值中的不可见字符。注释：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。

在使用前需要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