sql server 操作表字段

-- 在表orders_ana_2020_temp添加yg_headfee 字段

alter table orders_ana_2020_temp add yg_headfee decimal(10,2)

 

-- 修改已存在表字段类型
ALTER TABLE item_inf ALTER COLUMN mem nvarchar(1000)

 

-- 删除表Test1103中的字段yg_headfee
alter table Test1103 drop column yg_headfee

 

-- 查询指定表的字段信息

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 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.xtype=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 1=1 
and d.name='Test1103' -- 这里修改表名
and a.name='id' -- 这里修改字段名
order by a.id,a.colorder