20200224
1, Oracle version
Oracle9i Oracle10g Oracle11g Oracle12c
where i refers to the Internet, g is a grid, c is means cloud
2, account / password / login
Super administrators sys: change_on_install
General administrator system: mannager
Average user scott: tiger
Ordinary user's password after adding "as sysdba" current account can be set as a temporary administrator of super Denunciation failure
After using "sqlplus username / password" to login or "sqlplus" in the CMD window, enter the account number and password
Account switching: conn username / password
Password Review: super administrator input alter user username identified by password; the user name or password
Account Lock / Unlock: Enter the Administrator account username alter user account lock / unlock;
The failure password: alter user u1 password expire;
3, the operation window Black
set linesize integer; dark current window to set the number of characters per line of
set pagesize integer; The number of lines per page in the current window is black (contains empty lines + + header line rows), and blank lines every row header "integer" line that is repeated once.
spool saved address; save the black window to set the address of the page
spool off; black close Save Interface
clear screen; 清屏
ED: error code may be modified above, will pop up a file, close the file save modified, then R dos input window to be run again.
4, basic grammar
SQL is not case sensitive;
Some database systems require a semicolon at the end of each SQL statement;
The default date format for the '23 - January -1982 '
select: extract data from the database
Update data in the database: update
delete: delete data from the database
insert into: insert new data into the database
create database / table / index: create a database / table / index
alter database/table：修改数据库/表
drop table/index：删除表/索引
distinct：去除重复行，但distinct必须写在select后的第一个元素
dual：临时表（没有存在意义）
作者：kerwin-chyl
文章链接：https:////www.cnblogs.com/kerwin-chyl
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