如何使用sql查询数据库表结构的设计(sqlserver,oracle)

1、sqlserver(注：表名必须大写)

select a.name 表名,b.name 字段名,c.name 字段类型,c.length 字段长度 from sysobjects

a,syscolumns b,systypes c where a.id=b.id and a.name=’此处填写要查询的表名’ and

a.xtype=’U’ and b.xtype=c.xtype

2、Oracle(注：表名必须大写)

1、查询数据库表的字段信息

select

A.column_name 字段名,A.data_type 数据类型,A.data_length 长度,A.data_precision 整数位,

A.Data_Scale 小数位,A.nullable 允许空值,A.Data_default 缺省值,B.comments 备注 from

user_tab_columns A,user_col_comments B where

A.Table_Name = B.Table_Name

and A.Column_Name = B.Column_Name

and A.Table_Name = ‘此处添加要查询的表名’

2、查询数据库表的索引

select

INDEX_NAME 索引名,INDEX_TYPE 索引类型,UNIQUENESS 索引类别 from

user_indexes where

TABLE_NAME = ‘此处添加要查询的表名’

3、查询数据库某个表的超全信息

select

A.column_name 字段名,A.data_type 数据类型,A.data_length 长度,A.data_precision 整数位,

A.Data_Scale 小数位,A.nullable 允许空值,A.Data_default 缺省值,B.comments 备注,

C.IndexCount 索引次数 from

user_tab_columns A,

user_col_comments B,

(select count(*) IndexCount,Column_Name from User_Ind_Columns where Table_Name = ‘此处添加要查询的表名’ group by Column_Name) C where

A.Table_Name = B.Table_Name

and A.Column_Name = B.Column_Name

and A.Column_Name = C.Column_Name(+)

and A.Table_Name = ‘此处添加要查询的表名’

Oracle拓展：

– 创建数据表

create table TABLE_TEST (

NAME varchar2(40) not null,

SEX varchar2(1) default ””Y”” not null,

BIRTHDAY date not null,

HEIGHT number(3,2),

WEIGHT number(3,2),

MEMO blob );

– 给列添加备注

comment on column TABLE_TEST.NAME is ””姓名””; comment on column

TABLE_TEST.SEX is ””性别””; comment on column TABLE_TEST.BIRTHDAY

is ””生日””; comment on column TABLE_TEST.HEIGHT is ””身高””;

comment on column TABLE_TEST.WEIGHT is ””体重””; comment on column

TABLE_TEST.MEMO is ””备注””;

– 创建约束关系 主键 外键 其他

alter table TABLE_TEST add constraint TB_TEST_P_NAME primary key

(NAME);