SQL获取数据库名，表名，列名，说明等信息

由于最近工作涉及SQL语句较多，对一些不常见的SQL函数、及存储过程下面进行整理和描述，供大家分享：

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1、获取所有用户名:

islogin='1'   :表示帐户

islogin='0'   :表示角色

status='2'   :表示用户帐户

status='0'   :表示系统帐户

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SELECT name

FROM   sysusers

WHERE  status = '0'

       AND islogin = '1'

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2、获取所有数据库名:

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SELECT name

FROM     master..sysdatabases

ORDER BY name

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3、获取所有表名:

XType='U'    :表示所有用户表;

XType='S'    :表示所有系统表;

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SELECT name

FROM     数据库名..sysobjects

WHERE    xtype = 'U'

ORDER BY name

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4、获取所有字段名:

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SELECT name

FROM   syscolumns

WHERE  id = Object_id('表名')

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5、获取数据库所有类型:

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SELECT name

FROM   systypes

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6、获取主键字段:

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SELECT name

FROM   syscolumns

WHERE  id = Object_id('表名')

       AND colid = (SELECT TOP 1 keyno

                    FROM   sysindexkeys

                    WHERE  id = Object_id('表名'))

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7、获取表字段的基本信息:

a.

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SELECT 字段名 = Rtrim(b.name)

       ,主键 = CASE 

               WHEN h.id IS NOT NULL THEN 'PK'

               ELSE ''

             END

       ,字段类型 = Type_name(b.xusertype)

                + CASE 

                    WHEN b.colstat & 1 = 1 THEN '[ID('

                                                 + CONVERT(VARCHAR,Ident_seed(a.name))

                                                 + ','

                                                 + CONVERT(VARCHAR,Ident_incr(a.name))

                                                 + ')]'

                    ELSE ''

                  END

       ,长度 = b.length

       ,允许空 = CASE b.isnullable 

                WHEN 0 THEN 'N'

                ELSE 'Y'

              END

       ,默认值 = Isnull(e.TEXT,'')

       ,字段说明 = Isnull(c.VALUE,'')

FROM     sysobjects a

         INNER JOIN  sys.all_objects aa

           ON a.id=aa.object_id 

              AND  schema_name(schema_id)='dbo'

         ,syscolumns b

         LEFT OUTER JOIN sys.extended_properties c

           ON b.id = c.major_id

              AND b.colid = c.minor_id

         LEFT OUTER JOIN syscomments e

           ON b.cdefault = e.id

         LEFT OUTER JOIN (SELECT g.id

                                 ,g.colid

                          FROM   sysindexes f

                                 ,sysindexkeys g

                          WHERE  (f.id = g.id)

                                 AND (f.indid = g.indid)

                                 AND (f.indid > 0)

                                 AND (f.indid < 255)

                                 AND (f.status & 2048) <> 0) h

           ON (b.id = h.id)

              AND (b.colid = h.colid)

WHERE    (a.id = b.id)

         AND (a.id = Object_id('表名'))  --要查询的表改成你要查询表的名称

ORDER BY b.colid

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b.

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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

       ,字段长度 = a.length

       ,占用字节数 = 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') 

          INNER JOIN  sys.all_objects c

            ON d.id=c.object_id 

                AND  schema_name(schema_id)='dbo'

         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='要查询的表'         --如果只查询指定表,加上此条件

ORDER BY a.id

         ,a.colorder

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c. 前两种不完整~

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-- 資料庫中所有資料表：透過內定的Stored Procedure sp_tables

EXEC sp_tables @table_name = '%',@table_owner = 'dbo',@table_qualifier = @DBName; 

--    取得資料表Schema

EXEC sp_columns @TableName 

--    取得欄位說明、備註(Extended Property)：這個是透過Sql內定的Function來處理

SELECT * FROM  ::fn_listextendedproperty(NULL, 'user', 'dbo', 'table', @TableName, 'column', default) 

--    取得主索引

EXEC sp_pkeys @TableName 

 





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表及字段描述信息处理示例

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--创建表

CREATE TABLE 表 (

  a1  VARCHAR(10)

  ,a2 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'表' , NULL , NULL

EXEC sys.sp_addextendedproperty 

@name=N'MS_Description', @value=N'人员信息表' , 

@level0type=N'SCHEMA',@level0name=N'dbo', 

@level1type=N'TABLE',@level1name=N'表'

 





--为字段a1添加描述信息

EXECUTE Sp_addextendedproperty N'MS_Description' , '姓名' , N'user' , N'dbo' , N'table' , N'表' , N'column' , N'a1'

EXEC sys.sp_addextendedproperty 

@name=N'MS_Description', @value=N'人员信息表' , 

@level0type=N'SCHEMA',@level0name=N'dbo', 

@level1type=N'TABLE',@level1name=N'表', 

@level2type=N'COLUMN',@level2name=N'a1'



 





--为字段a2添加描述信息

EXECUTE Sp_addextendedproperty N'MS_Description' , '性别' , N'user' , N'dbo' , N'table' , N'表' , N'column' , N'a2'

--更新表中列a1的描述属性：

EXEC Sp_updateextendedproperty 'MS_Description' , '字段1' , 'user' , dbo , 'table' , '表' , 'column' , a1

--显示表的描述属性

SELECT *

FROM   ::fn_listextendedproperty(NULL,'user','dbo','table','表','column',NULL)

--删除表中列a1的描述属性：

EXEC Sp_dropextendedproperty 'MS_Description' , 'user' , dbo , 'table' , '表' , 'column' , a1

--删除测试

DROP TABLE 表