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SQL.Cookbook 读书笔记5 元数据查询

第五章 元数据查询 查询数据库本身信息 表结构 索引等

5.1 查询test库下的所有表信息

MYSQL

SELECT * from information_schema.`TABLES` WHERE TABLE_SCHEMA = test;

ORACLE

select table_name from all_tables where owner = test;

5.2 查询表中列的信息

MYSQL

SELECT * from information_schema.`COLUMNS` WHERE TABLE_SCHEMA = test AND TABLE_NAME = student;

ORACLE

select * from all_tab_columns where owner = test and table_name = student;

5.3 列出表的索引

MYSQL

show index from emp;

ORACLE

select table_name,index_name,column_name,column_position from sys.all_ind_columns where table_name = emp and table_owner = test;

5.4 列出表约束

ORACLE

select a.table_name,a.constraint_name,b.coulumn_name,a.constraint_type from all_constraints a,all_cons_columns b where a.table_name = EMP and a.owner = test and a.table_name = b.table_name and a. owner = b.owner and a.constraint_name = b.constraint_name;

MYSQL

select a.table_name,a.constraint_name,b.coulumn_name,a.constraint_type from information_schema.table_constraints a,information_schema.key_column_usage b where a.table_name = EMP and a.table_schema= test and a.table_name = b.table_name and a. table_schema = b.table_schema and a.constraint_name = b.constraint_name;

 5.5 显示表结构

desc user;

 

SQL.Cookbook 读书笔记5 元数据查询