查询表结构的SQL语句

declare @table_name as varchar(max)
set @table_name = '表名'
select sys.columns.name,
 sys.types.name, sys.columns.max_length,  sys.columns.is_nullable,
(select count(*) from sys.identity_columns 
where  sys.identity_columns.object_id = sys.columns.object_id and  sys.columns.column_id = sys.identity_columns.column_id) as is_identity ,
(select value from sys.extended_properties 
where  sys.extended_properties.major_id = sys.columns.object_id and  sys.extended_properties.minor_id = sys.columns.column_id) as description
from sys.columns, sys.tables, sys.types where sys.columns.object_id
=  sys.tables.object_id and
 sys.columns.system_type_id=sys.types.system_type_id
 and sys.tables.name=@table_name order by sys.columns.column_id