SQL语句PART11
1. My test: (create and grant the sysdba to a new user by SQL*Plus)
CREATE USER FJTEST1 IDENTIFIED BY JEANJEANFANG;
GRANT SYSDBA TO FJTEST;
REVOKE SYSDBA from FJTEST;
CONNECT FJTEST1/JEANJEANFANG AS SYSDBA;
2. Using ORAPWD in windows:
C:\» ORAPWD;
(show help information)
3. to see the password file:
Grammer: ORACLE_BASE\ORACLE_HOME\database» attrib
F:\oracle\ora92\database\attrib
** if want to create a user that can be connect as normal and can create table, you should grant “create session”, “resource” privileges to the user or it cannot connect as normal.
e.g.:
SQL»create user fj identified by fj;
SQL»grant create session to fj;
SQL»grant resource to fj;
Then the user “fj” can be connected as “normal” and the schema belonging to this user will be created, where he/she can create tables.
SQL» select * from user_sys_privs;
Use above statements to check user’s own system privileges.
2．How to create password file using ORAPWD
F:\oracle\ora92\database\ORAPWD FILE=F:\oracle=ora92\database\PWDmydb.ora PASSWORD=oracle ENTRIES=30
F:\oracle\ora92\database\sqlplus /nolog
SQL» connect SYS/oracle AS SYSDBA
ERROR: ORA-01031: insufficient privileges
(如果发生以上错误, 说明在ORACLE中开启了多于一个的数据库, 并且处于ＳＴＡＲＴＵＰ状态．此时要连接必须用: connect SYS/oracle＠SID AS SYSDBA, 必须在F:\oracle\ora92\network\admin＼ＴＮＳＮＡＭＥＳ．ＯＲＡ里面定义过， 如果连接的是个别数据库，就不会报告这样的错误)
ＴＮＳＮＡＭＥＳ．ＯＲＡ 定义方式：
FJDB.SIIC.COM =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = fangjin)(PORT = 1521))
)
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = fjdb)
)
)
** or use the following command in dos state:
C: \ set oracle_sid = “jeandb”
C:\ sqlplus /nolog
SQL» connect sys/jeandb as sysdba;
3. Ｈow to create an oracle database in windows manually
Step1: setting environment var
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第二十题：
怎么样抽取重复记录
表：
id name
--------
1 test1
2 test2
3 test3
4 test4
5 test5
6 test6
2 test2
3 test3
2 test2
6 test6
查出所有有重复记录的数据，用一句sql 来实现
create table D(
id varchar (20),
name varchar (20)
)
insert into D values('1','test1')
insert into D v ......
包由包规范和包体两部分组成。
1、包规范（Package Specification）
包规范，也叫做包头，包含了有关包的内容的信息。但是，它不包含任何过程的代码。
创建包头的语法一般如下
CREATE [OR REPLACE] PACKAGE package_name {IS | AS}
Procedure_name | function_name | variable_declaration | type_def ......
oracle 方法 & ......
Merge statement
function benefits: 1) provides the ability to conditionally update, insert or delete data into a database table. 2) performs an update if the row exists, and an insert if it is a new row. --> 1) avoids seperate updates, 2) increase performance and ease of use. 3) is useful in dat ......
Group functions
SELECT [column,] group_function(column) ... from table [WHERE condition] [GROUP BY group_by_expression] [ORDER BY column];
e.g.:
SELECT department_id, job_id, SUM(salary), COUNT(employee_id) from employees GROUP BY department_id, job_id ;
SELECT [column,] group_function(column).. ......
