sqlserver查询列名、注释类型、长度、是否为空

SELECT 
    表名       = case when a.colorder=1 then d.name else '' end,
    表说明     = case when a.colorder=1 then isnull(f.value,'') else '' end,
    字段序号   = a.colorder,
    字段名     = a.name,
    标识       = case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else '' end,
    主键       = case when exists(SELECT 1 FROM sysobjects where xtype='PK' and parent_obj=a.id and name in (
                     SELECT name FROM sysindexes WHERE indid in( SELECT indid FROM sysindexkeys WHERE id = a.id AND colid=a.colid))) then '√' else '' end,
    类型       = b.name,
    占用字节数 = a.length,
    长度       = COLUMNPROPERTY(a.id,a.name,'PRECISION'),
    小数位数   = isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0),
    允许空     = case when a.isnullable=1 then '√'else '' end,
    默认值     = isnull(e.text,''),
    字段说明   = isnull(g.[value],'')
FROM 
    syscolumns a
left join 
    systypes b 
on 
    a.xusertype=b.xusertype
inner join 
    sysobjects d 
on 
    a.id=d.id  and d.xtype='U' and  d.name<>'dtproperties'
left join 
    syscomments e 
on 
    a.cdefault=e.id
left join 
sys.extended_properties   g 
on 
    a.id=G.major_id and a.colid=g.minor_id  
left join
sys.extended_properties f
on 
    d.id=f.major_id and f.minor_id=0
--where 
--    d.name='tableName'    --如果只查询指定表,加上此红色where条件，tablename是要查询的表名；去除红色where条件查询说有的表信息
order by 
    a.id,a.colorder