Oracle

Oracle has 3 types of users:System, SYS, Scott, where the difference between system and SYS is with the ability to create a database, the SYS user is able to log in enough to create a database, and Scott is the user who learns from the beginning of

Silent Installation Reference: http://www.cnblogs.com/colmeluna/p/5686142.htmlIn the actual installation:1. Skip the second step to set the swap area space2. No prompt to execute orainstroot.sh after installation is complete, only root.shBuild

Oracle because of its own multi-factor authentication mechanism all in the delete table space is not like MySQL delete database, can be deleted by the external Delete database folder can delete database, of course, these two are 2 different things,

Sql> Select COUNT (*) from V$session #当前的连接数Sql> Select Count (*) from v$session where status= ' ACTIVE ' #并发连接数Sql> Select value from v$parameter where name = ' processes '--the maximum number of connections allowed for the databaseSql> Show

ReasonIn the process of operating the database, we may encounter this situation, the data in the table may be repeated, so that we have a lot of difficulties in the operation of the database, so how to delete these duplicate data?You may encounter a

Three functions(1.) Single-line function, one-to-a-row record corresponds to a result(2) Multi-line function, many-to-one, multi-line records corresponding to a result1. Character functionsAs for lower and upper when to use, such as do not know the

Cursor Concept: A cursor is a PL/SQL control structure that enables the display control of the processing of the statement, making it easier to process the row data of the table. Cursors are not database objects, but are persisted in

Select Sal,sal as Saly from EMP;--to find the average of a columnSELECT * from EMP;--Select Sal as NB from EMP;--Sort By default ascending ASC Nearest principleSELECT * from emp order by Empno,sal;--Descending descSELECT * from emp order BY Sal Desc;

Before we introduce the group BY and HAVING clause, we must first talk about a special function in the SQL language: aggregate functions such as SUM, COUNT, MAX, AVG, and so on. The fundamental difference between these functions and other functions

************************************************************************* * * * Original:blog.csdn.net/clark_xu Xu Changliang's Column************************************************************************Description of the problem:Original SGA 4G.

Stored Procedure Basic syntaxHttp://www.cnblogs.com/hero4china/articles/base_rule_oracle_procedure.htmlBasic notation for Stored proceduresHttp://www.linuxidc.com/Linux/2013-11/93196.htmA simple example of a stored

The default table for Oracle's Scott usersEMP (Employee table)NO Field type description1 EMPNO Number (4) Employee ID2 ename VARCHAR2 (10) indicates employee name3 Job VARCHAR2 (9) indicates jobs4 MGR Number (4) indicates an employee's leader ID5

1. Download and install Oracle Developer Tools for Visual Studio;2. Configure Tnsnames.oraOdp. NET by default using the installation directory tnsnames.ora , if the installation directory under Program files, you may encounter problems such as no

Small series often encountered "error" when using OracleORA-12541:TNS: No listener ""Multi-party search, find a good solution, to share with you: 1Open "Oracle Net configuration Assistance" from the Start menu, select "Listener Configuration"

Import all tables and data for a user:Imp sgp/[email PROTECTED]:1521/ORCL file=sgp20161025.dmp full=yTo export the specified tables and data:Exp Sgp/[email PROTECTED]:1521/ORCL file=20160921sgp_table_sysmodule_sysdict.dmp tables= (Sgp_sysmodule, sgp_

Data type:Character typeChar fixed length, maximum 2000 charactersvarchar LONG, max 4000 charactersCLOB (character large object) character type large objects, Max 4GNumber TypeNumber Range (10-38 Square to 10 38-square, fractional integer

Oracle driver= "Oracle.jdbc.driver.OracleDriver" url= "Jdbc:oracle:thin: @localhost: 1521: Database name" SQL Server driver= "Com.microsoft.jdbc.sqlserver.SQLServerDriver" url= "jdbc:microsoft:sqlserver://localhost:1433 ;D atabasename= database

LOGIN: Conn username/passwordCreate user user name identified by passwordChange Password Password user nameDelete User drop username userIf the user you want to delete has already created the table, then delete the parameter cascadeGrant permission

There are two reasons why Oracle table space is low:1. The original table space is too small, no self-growth;2. Table space has grown and table space is large enoughCheck Cause:1. View the table in that table spaceSelectTablespace_name,table_name

http://blog.csdn.net/haibusuanyun/article/details/16338591bash-3.2$lsnrctl StatusLsnrctl for linux:version 11.2.0.1.0-production on 16-jul-2017 23:12:16Copyright (c) 1991, Oracle. All rights reserved.Connecting to (Description= (address=