怎样把所有text类型并且为空的字段改为" "

[TsungLee]

因为用jdbc查询的时候会出错，所以要重新修改数据库。
怎样把表里面所有text类型并且为null的字段，update为" "呢？
如果能对整个数据库操作就更好，因为我有两个数据库，n多个表要修改的。

请各位高手指教。

[wgsasd311]

--try
if exists(select 1 from sysobjects where xtype='p' and name='update_null')
drop proc update_null
go
/*
功能:处理表中"text"和"ntext"类型字段中的NULL值,用''替换
作者:WGS
创建时间:2006-06-14
调用事例:
1。对一个表操作：update_null 'tb1'
2。对整个数据库操作：sp_msforeachtable "update_null '?'"
*/
create proc update_null(@tbname nvarchar(50))
as
declare @fld varchar(20),@ftype varchar(30),@fid int,@sql varchar(300)
declare cur cursor for
select a.name,b.name,a.xusertype from syscolumns a,systypes b
where a.xusertype=b.xusertype and a.id=object_id(@tbname) order by b.xusertype
open cur
fetch next from cur into @fld,@ftype,@fid
while @@fetch_status=0
begin
if @ftype in('text','ntext')
exec('update '+@tbname+' set '+@fld+'='''' where '+@fld+' is null')
fetch next from cur into @fld,@ftype,@fid
end
close cur
deallocate cur

go

[lxzm1001]

update tablename set textcol=''

[xeqtr1982]

update 表 set 字段='' where 字段 is NULL

[fengfangfang]

update tablename set textcol=''
from tablename
where textcol is null

[edp08]

在系统表中找出所有表\所有字段(用游标装着),然后循环判断是否text类型字段,是就拼一条SQL,然后执行之

应该很容易写的,不会超过二十条语句

[xeqtr1982]

declare @sql varchar(8000)
set @sql=''
select @sql=@sql+'update ['+b.name+'] set ['+a.name+']='''' where ['+a.name+'] is NULL;' from syscolumns a,sysobjects b,systypes c where a.id=b.id and b.xtype='U' and a.xtype=c.xtype and c.name in('text')
exec(@sql)

[wgsasd311]

if exists(select 1 from sysobjects where xtype='p' and name='update_null')
drop proc update_null
go
/*
功能:处理表test字段中的NULL值,用''替换
作者:WGS
创建时间:2006-06-14
调用事例:
1。对一个表操作：update 'tb1'
2。对整个数据库操作：sp_msforeachtable "update '?'"
*/
create proc update_null(@tbname nvarchar(50))
as
declare @fld varchar(20),@ftype varchar(30),@fid int,@sql varchar(300)
declare cur cursor for
select a.name,b.name,a.xusertype from syscolumns a,systypes b
where a.xusertype=b.xusertype and a.id=object_id(@tbname) order by b.xusertype
open cur
fetch next from cur into @fld,@ftype,@fid
while @@fetch_status=0
begin
if @ftype in('text','ntext')
exec('update '+@tbname+' set '+@fld+'='''' where '+@fld+' is null')
fetch next from cur into @fld,@ftype,@fid
end
close cur
deallocate cur

go
--

[wgsasd311]

--try
if exists(select 1 from sysobjects where xtype='p' and name='update_null')
drop proc update_null
go
/*
功能:处理表test字段中的NULL值,用''替换
作者:WGS
创建时间:2006-06-14
调用事例:
1。对一个表操作：update_null 'tb1'
2。对整个数据库操作：sp_msforeachtable "update_null '?'"
*/
create proc update_null(@tbname nvarchar(50))
as
declare @fld varchar(20),@ftype varchar(30),@fid int,@sql varchar(300)
declare cur cursor for
select a.name,b.name,a.xusertype from syscolumns a,systypes b
where a.xusertype=b.xusertype and a.id=object_id(@tbname) order by b.xusertype
open cur
fetch next from cur into @fld,@ftype,@fid
while @@fetch_status=0
begin
if @ftype in('text','ntext')
exec('update '+@tbname+' set '+@fld+'='''' where '+@fld+' is null')
fetch next from cur into @fld,@ftype,@fid
end
close cur
deallocate cur

go

[xeqtr1982]

如果动态@sql变量长度不足，可考虑多个变量连接。

或采用游标

[TsungLee]

先谢谢大家的帮忙。

尝试了xeqtr1982(Visual C# .NET)和wgsasd311(自强不息) 的办法，但都出现这个报错：

子查询返回的值多于一个。当子查询跟随在 =、!=、<、<=、>、>= 之后，或子查询用作表达式时，这种情况是不允许的。
语句已终止。