sql server or Oracle: table MS_Description

--SQL Server表描述 及 字段描述的增、删、改、查询
--sql server 2000系统表sysproperties在SQL 2008中无效的问题   今天无意中在网上发现Sqlserver有一个扩展属性系统表sysproperties，因为只接触过MSSQL2005及以后的版本，在生产库2008版本及联机文档上搜了下都找不到这个系统表，后来发现这个系统表在2005版本后就被另一个系统表sys.extended_properites所代替。
--select * from sys.extended_properites where major_id = object_id and name = 'MS_Description'
--测试:
--创建表及描述信息
create table geovindu(duname varchar(10),isname char(2))
--为表添加描述信息
EXECUTE sp_addextendedproperty N'MS_Description', '人员信息表', N'user', N'dbo', N'table', N'geovindu', NULL, NULL
--为字段duname添加描述信息
EXECUTE sp_addextendedproperty N'MS_Description', '姓名', N'user', N'dbo', N'table', N'geovindu', N'column', N'duname'
--为字段isname添加描述信息
EXECUTE sp_addextendedproperty N'MS_Description', '性别', N'user', N'dbo', N'table', N'geovindu', N'column', N'isname'
--更新表中列duname的描述属性：
EXEC sp_updateextendedproperty 'MS_Description',N'聚文','user',dbo,'table','geovindu','column',duname
EXEC sp_updateextendedproperty N'MS_Description', '涂聚文', N'user', N'dbo', N'table', N'geovindu', N'column', N'duname'
--删除表中列duname的描述属性：
EXEC sp_dropextendedproperty 'MS_Description','user',dbo,'table','geovindu','column',duname
--至于查询出来，sql server有提供系统函数fn_listextendedproperty ()：
--获取某一个字段的描述
SELECT * FROM ::fn_listextendedproperty (NULL, 'user', 'dbo', 'table', 'geovindu', 'column', default)
--其他变数，按照你的要求你照写即可，只要表名换成你的where objname = '字段名
--删除测试
drop table geovindu
go

---1.SQL查询表的所有字段的备注说明
SELECT Sysobjects.name AS TABLE_NAME, syscolumns.Id, syscolumns.name AS COLUMN_NAME,
systypes.name AS DATA_TYPE, syscolumns.length as CHARACTER_MAXIMUM_LENGTH,
sys.extended_properties.[value] AS COLUMN_DESCRIPTION,  syscomments.text as
COLUMN_DEFAULT,syscolumns.isnullable as IS_NULLABLE FROM syscolumns
INNER JOIN systypes
    ON syscolumns.xtype = systypes.xtype
    LEFT JOIN sysobjects ON syscolumns.id = sysobjects.id
  LEFT OUTER JOIN sys.extended_properties ON
  ( sys.extended_properties.minor_id = syscolumns.colid
    AND sys.extended_properties.major_id = syscolumns.id)
  LEFT OUTER JOIN syscomments ON syscolumns.cdefault = syscomments.id
  WHERE syscolumns.id IN
    (SELECT id FROM SYSOBJECTS WHERE xtype = 'U') AND (systypes.name <> 'sysname')
    ORDER BY syscolumns.colid

--2.SQL查询表的所有字段的备注说明
SELECT
(case when a.colorder=1 then d.name else '' end) N'表名',
a.colorder N'字段序号',
a.name N'字段名',
(case when COLUMNPROPERTY( a.id,a.name,'IsIdentity')=1 then '√'else ''
end) N'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) N'主键',
b.name N'类型',
a.length N'占用字节数',
COLUMNPROPERTY(a.id,a.name,'PRECISION') as N'长度',
isnull(COLUMNPROPERTY(a.id,a.name,'Scale'),0) as N'小数位数',
(case when a.isnullable=1 then '√'else '' end) N'允许空',
isnull(e.text,'') N'默认值',
isnull(g.[value],'') AS N'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 object_name(a.id),a.colorder
--3. SQL 2005查询表的所有字段的备注说明
SELECT
TableName=CASE WHEN C.column_id=1 THEN O.name ELSE N'' END,
TableDesc=ISNULL(CASE WHEN C.column_id=1 THEN PTB.[value] END,N''),
Column_id=C.column_id,
ColumnName=C.name,
PrimaryKey=ISNULL(IDX.PrimaryKey,N''),
[IDENTITY]=CASE WHEN C.is_identity=1 THEN N'√'ELSE N'' END,
Computed=CASE WHEN C.is_computed=1 THEN N'√'ELSE N'' END,
Type=T.name,
Length=C.max_length,
Precision=C.precision,
Scale=C.scale,
NullAble=CASE WHEN C.is_nullable=1 THEN N'√'ELSE N'' END,
[Default]=ISNULL(D.definition,N''),
ColumnDesc=ISNULL(PFD.[value],N''),
IndexName=ISNULL(IDX.IndexName,N''),
IndexSort=ISNULL(IDX.Sort,N''),
Create_Date=O.Create_Date,
Modify_Date=O.Modify_date
FROM sys.columns C
INNER JOIN sys.objects O
ON C.[object_id]=O.[object_id]
AND O.type='U'
AND O.is_ms_shipped=0
INNER JOIN sys.types T
ON C.user_type_id=T.user_type_id
LEFT JOIN sys.default_constraints D
ON C.[object_id]=D.parent_object_id
AND C.column_id=D.parent_column_id
AND C.default_object_id=D.[object_id]
LEFT JOIN sys.extended_properties PFD
ON PFD.class=1
AND C.[object_id]=PFD.major_id
AND C.column_id=PFD.minor_id
-- AND PFD.name='Caption' -- 字段说明对应的描述名称(一个字段可以添加多个不同name的描述)
LEFT JOIN sys.extended_properties PTB
ON PTB.class=1
AND PTB.minor_id=0
AND C.[object_id]=PTB.major_id
-- AND PFD.name='Caption' -- 表说明对应的描述名称(一个表可以添加多个不同name的描述)
LEFT JOIN -- 索引及主键信息
(
SELECT
IDXC.[object_id],
IDXC.column_id,
Sort=CASE INDEXKEY_PROPERTY(IDXC.[object_id],IDXC.index_id,IDXC.index_column_id,'IsDescending')
WHEN 1 THEN 'DESC' WHEN 0 THEN 'ASC' ELSE '' END,
PrimaryKey=CASE WHEN IDX.is_primary_key=1 THEN N'√'ELSE N'' END,
IndexName=IDX.Name
FROM sys.indexes IDX
INNER JOIN sys.index_columns IDXC
ON IDX.[object_id]=IDXC.[object_id]
AND IDX.index_id=IDXC.index_id
LEFT JOIN sys.key_constraints KC
ON IDX.[object_id]=KC.[parent_object_id]
AND IDX.index_id=KC.unique_index_id
INNER JOIN -- 对于一个列包含多个索引的情况,只显示第1个索引信息
(
SELECT [object_id], Column_id, index_id=MIN(index_id)
FROM sys.index_columns
GROUP BY [object_id], Column_id
) IDXCUQ
ON IDXC.[object_id]=IDXCUQ.[object_id]
AND IDXC.Column_id=IDXCUQ.Column_id
AND IDXC.index_id=IDXCUQ.index_id
) IDX
ON C.[object_id]=IDX.[object_id]
AND C.column_id=IDX.column_id
 --WHERE O.name=N'geovindu' -- 如果只查询指定表,加上此条件
ORDER BY O.name,C.column_id

SELECT * FROM sys.extended_properties

 --显示所有表和描述
SELECT * FROM sys.objects WHERE type='u' AND object_id=5575058
SELECT * FROM sys.extended_properties WHERE minor_id=0  AND major_id=5575058

SELECT obj.name AS [TableName],pro.value AS [Description] FROM sys.objects obj LEFT JOIN sys.extended_properties pro
ON obj.object_id=pro.major_id
WHERE obj.type='u'

 --显示所有表的字段描述 

 SELECT * FROM sys.extended_properties WHERE minor_id>0

SELECT * FROM sys.extended_properties WHERE  major_id=789577851

SELECT * FROM sys.columns WHERE object_id=789577851

SELECT obj.name AS [TableName], col.name AS [ColumnName],pro.value AS [Description] FROM sys.columns col,sys.extended_properties pro,sys.objects obj
WHERE col.object_id=pro.major_id
AND col.column_id=pro.minor_id
AND obj.object_id=col.object_id

 ---LibraryDu  BookInfoList
 --一个表的备注信息
SELECT objtype, objname, [name], [value]
FROM fn_listextendedproperty (NULL, 'schema', 'dbo', 'table', 'BookInfoList', NULL, NULL);
GO
--所有表的备注信息
SELECT objtype, objname, [name], [value]
FROM fn_listextendedproperty (NULL, 'schema', 'dbo', 'table', null, NULL, NULL);
GO

SELECT objtype, objname, [name], [value]
FROM fn_listextendedproperty (NULL, 'user', 'dbo', 'table', null, NULL, NULL);
GO

　　Oracle:

--对表的说明
comment on table BookKindList is '书分类目录';
--对表中列的说明
comment on column BookKindList.BookKindID is '目录ID';
comment on column BookKindList.BookKindName is '目录名称';
comment on column BookKindList.BookKindParent is '目录父ID';
comment on column BookKindList.BookKindCode is '目录code';

declare
gg nvarchar2(500):='geovindu2';
dd nvarchar2(500):='d';
begin
select REPLACE(gg, chr(10), '') into dd from dual;
dbms_output.put_line(dd);
end;

select * from user_tab_comments;

select *  from user_col_comments;

--
/*
user_tab_comments;表注释

        user_col_comments;表字段注释

        以上两个只能获取自己用户的表的注释信息，如果要访问自己能够访问的其他用户的表，则需要使用：

        all_tab_comments;表注释

        all_col_comments;表字段注释

        当然，如果有DBA权限，则可以使用

        dba_tab_comments;表注释

        dba_col_comments;表字段注释

        dba*和all*最好指定owner条件。user*没有该字段

        user_tab_comments;表注释

        user_col_comments;表字段注释

        以上两个只能获取自己用户的表的注释信息，如果要访问自己能够访问的其他用户的表，则需要使用：

        all_tab_comments;表注释

        all_col_comments;表字段注释

        当然，如果有DBA权限，则可以使用

        dba_tab_comments;表注释

        dba_col_comments;表字段注释
*/