内容分别贴一下: select len(RTRIM(字段)),字段 from table select [列名]=a.Name, [列序号]=a.Column_id, [标识]=case when is_identity=1 then '√' else '' end, [主键]=case when exists(select 1 from sys.objects x join sys.indexes y on x.Type=N'PK' and x.Name=y.Name join sysindexkeys z on z.ID=a.Object_id and z.indid=y.index_id and z.Colid=a.Column_id) then '√' else '' end, [类型]=b.Name, [字节数]=case when a.[max_length]=-1 and b.Name!='xml' then 'max/2G' when b.Name='xml' then '2^31-1字节/2G' else rtrim(a.[max_length]) end, [长度]=case when ColumnProperty(a.object_id,a.Name,'Precision')=-1 then '2^31-1' else rtrim(ColumnProperty(a.object_id,a.Name,'Precision')) end, [小数]=isnull(ColumnProperty(a.object_id,a.Name,'Scale'),0), [是否为空]=case when a.is_nullable=1 then '√' else '' end, [默认值]=isnull(d.text,'') from sys.columns a left join sys.types b on a.user_type_id=b.user_type_id inner join sys.objects c on a.object_id=c.object_id and c.Type='U' left join syscomments d on a.default_object_id=d.ID where c.Name='表名' and a.name ='字段名'
用 nvarchar加长一点....
select DATALENGTH(字段),字段 from table
select DATALENGTH(字段),字段 from table
服务器却 占 20编码格式吗?
select len(RTRIM(字段)),字段 from table
select
[列名]=a.Name,
[列序号]=a.Column_id,
[标识]=case when is_identity=1 then '√' else '' end,
[主键]=case when exists(select 1 from sys.objects x join sys.indexes y on x.Type=N'PK' and x.Name=y.Name
join sysindexkeys z on z.ID=a.Object_id and z.indid=y.index_id and z.Colid=a.Column_id)
then '√' else '' end,
[类型]=b.Name,
[字节数]=case when a.[max_length]=-1 and b.Name!='xml' then 'max/2G'
when b.Name='xml' then '2^31-1字节/2G'
else rtrim(a.[max_length]) end,
[长度]=case when ColumnProperty(a.object_id,a.Name,'Precision')=-1 then '2^31-1'
else rtrim(ColumnProperty(a.object_id,a.Name,'Precision')) end,
[小数]=isnull(ColumnProperty(a.object_id,a.Name,'Scale'),0),
[是否为空]=case when a.is_nullable=1 then '√' else '' end,
[默认值]=isnull(d.text,'')
from
sys.columns a
left join
sys.types b on a.user_type_id=b.user_type_id
inner join
sys.objects c on a.object_id=c.object_id and c.Type='U'
left join
syscomments d on a.default_object_id=d.ID
where c.Name='表名' and a.name ='字段名'
问题出在该表table上,因为该表所有的字符类型的长度加起来,如果是varchar超过了8000,如果是nvarchar超过了4000,不信你可以加加看。表的字段可以定义varchar超过8000的,但是实际的数据长度不能超过,比如table表有两个字段,一个是varchar(8000),一个是varchar(50),varchar(50)能存进多少是看varchar(8000)里有多少字符了,如果有7000,varchar(50)肯定能全存进去,但是如果有7980,varchar(50)就只能存20了
insert into a_a_test(a,b,c)
select replicate('1234567890',800),replicate('1234567890',800),replicate('1234567890',800)
select * from a_a_test