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This article mainly explains "oracle query related command arrangement," interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let's let Xiaobian take you to learn "oracle query related command sorting"!

---

manually create

reference creating

e1 emp ---- ename,sal,deptno

sal--gz

create table e1 (ename,gz,deptno) as select ename,sal,deptno from emp;

create table e2 as select ename, sal gz,deptno from emp;

--CREATE

--TRUNCATE TABLE T1;

--ALTER

Column Name Data Type Length Increase Column Delete Column

--Increase

ALTER TABLE XXX ADD （address varchar2(10),sex varchar2(20)）;

--Delete

ALTER TABLE XXX DROP COLUMN XXX;

ALTER TABLE XXX DROP （XXXX，XXX）

--Modify Type Length Modify Type

ALTER TABLE XXX MODIFY （empno number(10)）

--Change column name

ALTER TABLE XXX RENAME COLUMN old TO new;

--RENAME Modify table name

RENAME old TO new;

---DROP Delete Table

DROP TABLE xxx

show recyclebin

purge

drop table xxx purge;

flashback table xxx to before drop rename to xxx;

---COMMENT

Table comment on table xx is ' '

column

-------------------------

DML

INSERT INTO xxx VALUES (xxx,xxx,xxx);

UPDATE

DELETE

NCHAR

NVARCHAR2

create table t1 (name nvarchar2(20));

BJ 2000km GZ

aircraft

train

automobile

bicycle

Route 11 500KM/H 4

merge collaborative update

A--------B

merge into myemp m

using emp e

on (e.empno=m.empno)

when matched then

update set m.ename=e.ename,m.sal=e.sal;

merge into p1

using p2

on (p2.empno=p1.empno)

when not matched then

insert values(p2.empno,p2.sal,p2.ename);

---------------------------------------------------------------------

TCL

commit

rollback

---savepoint

The four attributes ACID of transactions are Atomicity, Consistency, Isolation and Durability.

transaction

Basic Attributes 4 A C I D

tj (ename , sal)

a---1000----b

update tj set sal=sal-1000 where ename='A'

update tj set sal=sal+1000 where ename='B'

began

The first DML statement.

At this point, I believe we have a deeper understanding of "oracle query related command finishing", may wish to actually operate it! Here is the website, more related content can enter the relevant channels for inquiry, pay attention to us, continue to learn!

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