表或表字段等的注释，是数据库对象的扩展属性。在MSSQL中，支持把一些注释性的内容放到数据库或数据库对象中，增强可读性，有助于日后的管理和维护工作。扩展属性的内容可以通过SSMS添加、修改或删除，也可以通过系统视图查询，通过执行相关的存储过程来维护。
information_schema：系统视图
sys.extended_properties：系统视图
- 一、sqlserver 查询某个表的列名称、说明、备注、类型等
- 二、查询一个表的所有列名
- 三、查询一个表的所有列名，字段的注释
- 四、查询整个数据库语句
一、sqlserver 查询某个表的列名称、说明、备注、类型等
--sqlserver 查询某个表的列名称、说明、备注、类型等
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 = "数据库表名" --如果只查询指定表,加上此where条件，tablename是要查询的表名；去除where条件查询所有的表信息
order by
a.id,
a.colorder
效果如图：
二、查询一个表的所有列名
--查询一个表的所有列名
Select Name FROM SysColumns Where id=Object_Id("查询的数据库表名")
GO
select t.column_name from information_schema.columns t where t.table_name="查询的数据库表名";
第一局执行效果图：
第二句执行效果图：
三、查询一个表的所有列名，字段的注释
------查询一个表的所有列名，字段的注释
SELECT
A.name AS 表名,
B.name AS 字段名,
C.value AS 字段说明
FROM sys.tables A
INNER JOIN sys.columns B ON B.object_id = A.object_id
LEFT JOIN sys.extended_properties C ON C.major_id = B.object_id AND C.minor_id = B.column_id
WHERE A.name = "查询的数据库表名"
效果如图：
四、查询整个数据库语句
-- 名名称和字段名
SELECT
(
CASE WHEN a.colorder = 1 THEN d.name ELSE "" END
) 表名,
a.colorder 字段序号,
a.name 字段名,
(
CASE WHEN COLUMNPROPERTY(a.id, a.name, "IsIdentity") = 1 THEN "√" ELSE "" END
) 标识,
(
CASE WHEN (
SELECT
COUNT(*)
FROM
sysobjects
WHERE
(
NAME IN (
SELECT
NAME
FROM
sysindexes
WHERE
(id = a.id)
AND (
indid IN (
SELECT
indid
FROM
sysindexkeys
WHERE
(id = a.id)
AND (
colid IN (
SELECT
colid
FROM
syscolumns
WHERE
(id = a.id)
AND (NAME = a.name)
)
)
)
)
)
)
AND (xtype = "PK")
) > 0 THEN "√" ELSE "" END
) 主键,
b.name 类型,
a.length 占用字节数,
COLUMNPROPERTY(a.id, a.name, "PRECISION") AS 长度,
ISNULL(
COLUMNPROPERTY(a.id, a.name, "Scale"),
0
) AS 小数位数,
(
CASE WHEN a.isnullable = 1 THEN "√" ELSE "" END
) 允许空,
ISNULL(e.text, "") 默认值,
ISNULL(g.[value], "") AS 字段说明
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
ORDER BY
a.id,
a.colorder
