Oracle database knowledge points (I)

Catalog

Preface ：

One ． Introduction part

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Preface ：

ORACLE Five types of integrity constraints are supported

NOT NULL ( Non empty )-- prevent NULL Value into the specified column , Define... On a single column basis , By default ,ORACLE Allow... In any column NULL value .

CHECK ( Check )-- Check whether the conditions specified in the constraint are met .

UNIQUE ( only )-- Ensure that there are no duplicate values in the specified column . Each value or group of values in the table will be unique .

PRIMARY KEY ( Primary key )-- Used to uniquely identify each row of the table , And prevent NULL value , A table can only have one primary key constraint .

FOREIGN KEY ( External key )-- Establish a parent-child relationship between tables by using common columns (parent-child) Relationship , The external key defined on the table can point to the primary key or the unique key of other tables .ORACLE Five types of integrity constraints are supported

NOT NULL ( Non empty )-- prevent NULL Value into the specified column , Define... On a single column basis , By default ,ORACLE Allow... In any column NULL value .

CHECK ( Check )-- Check whether the conditions specified in the constraint are met .

UNIQUE ( only )-- Ensure that there are no duplicate values in the specified column . Each value or group of values in the table will be unique .

PRIMARY KEY ( Primary key )-- Used to uniquely identify each row of the table , And prevent NULL value , A table can only have one primary key constraint .

POREIGN KEY ( External key )-- Establish a parent-child relationship between tables by using common columns (parent-child) Relationship , The external key defined on the table can point to the primary key or the unique key of other tables .

One ． Introduction part

1.      Create tablespace

create tablespace schooltbs datafile ‘D:\oracle\datasource\schooltbs.dbf’ size 10M autoextend on;

2.      Delete tablespace

drop tablespace schooltbs[including contents and datafiles];

3.      Query the basic information of table space

select *||tablespace_name from DBA_TABLESPACES;

4.      Create user

create user  lihua

identified by lihua

default tablespace schooltbs

temporary tablespace temp;

5.      Change user

alter user lihua

identified by 123

default tablespace users;

6.      Lock the user

alter user lihua account lock|unlock;

7.      Delete user

drop user lihua cascade;-- Delete user mode 

8.      oracle Roles in the database

connect,dba,select_catalog_role,delete_catalog_role,execute_catalog_role,exp_full_database,imp_full_database,resource

9.      Grant the role of connecting to the server

grant connect to lihua;

10.   Grant roles that use tablespaces

grant resource to lihua with grant option;-- The user also has authorized permission 

11.   Grant permissions to the operation table

grant select,insert on user_tbl to scott;-- The current user 

grant delete,update on lihua.user_tbl to scott;-- System administrator 

12.   Modify the structure of the table (alter)

Alter table   Table name  add( Column name , The type of the column );