Oracle

I often read some articles to solve many of my own problems, but I am always embarrassed to read the articles that others read. After all, I learned others' experience and improved myself, but I didn't share it with others. I also want to write some

Add columns automatically for building: create sequence emp_sequence increment by 1 ---- add several minvalue 1 at a time ---- the minimum value is 1 nomaxvalue ---- do not limit the maximum value start with 1 ---- cache 10 from 1 ---- cache

Oracle Startup Process Analysis:Oracle generally has several statuses: shutdown, nomount, mount, and open. shutdown to nomount: oracle loads the initialization file to the default directory based on the sid in the environment variable, there are two

1. You have logged on to sqlplus/as sysdba: C: \ Documents and Settings \ Administrator> sqlplus/nolog SQL * Plus as a dba: release 10.2.0.3.0-Production on Wed Mar 28 00:21:32 201 Copyright (c) 1982,200 6, Oracle. all Rights Reserved. SQL> conn/as

Oracle time-type query Oracle query date can use =, but the data types must be consistent on both sides of the equal sign, for example, '2014-9-19 'is a string that cannot be directly compared with a date field and must be converted to a date string

Oracle-After configuring the local database to configure the local database, you can import the server data to the local database. The procedure is as follows:1. Enter the PL/SQL Developer login page, enter the Administrator's username and password (

The oracle Net Manager Service name cannot be configured. Today, when you configure the oracle Net Manager Service name, the service name configured previously cannot be displayed, then, clicking the green Add button does not respond, because I

After a piece of SQL code is written, you can view the SQL Execution Plan To preliminarily predict the performance of the SQL statement at run time, especially when the efficiency of an SQL statement is found to be poor, we can view the execution

On the Linux platform, Oracle Installation reports an error. Check if the DISPLAY variable is set. Solution: Install Oracle 11.2.0.3 on Oracle Linux 6.1. When running runInstaller, an error is reported.Details: [root @ dave mnt] # xhost + access

Synonyms are aliases of database objects. Oracle can create a specific alias for tables, views, sequences, stored procedures, functions, and packages.Two types of synonyms:> Private SYNONYM: a user (including non-administrator users) with the create

Oracle simple query statement 1. select * from emp where deptno = 30; 2. select all employees in department 30. list the names, numbers, and department numbers of all clerks. select ename, empno, deptno from emp WHERE job = 'cler'; 3. select * from

Oracle modifies the Data Type of a field in three ways: 1. set this column to null and modify its type (this will result in data loss. the simplest method is to assume that your table is named tab_target create table test as select * from tab_target

ORA-01461: can bind a LONG value only for insert into a LONG column solution my environment is ssh + oracle11.0. This error may be caused by your driver because the previous project was used mysql database, so there is no problem with using the

First introduce the Syntax: wmsys. wm_concat Definition: The Oracle PL/SQL WM_CONCAT function is used to aggregate data from a number of rows into a single row, giving a list of data associated with a specific value. in effect, it cross-tabulates a

The solution for Oracle 11g R2 to export empty tables with exp is a new feature in 11G R2. When there is no data in the table, no segment is allocated to save space. Of course, when Oracle executes export, empty tables cannot be exported, but there

Oracle instant client has recently been used to reinstall the operating system. It uses the Windows 7 x64 version and is not prepared to install Oracle. So we can see the Instant Client on the official website. Xing rushed to download a 64-bit

Due to the lock mechanism, when execution of a DML or ddl SQL statement is blocked, you need to find out why the SQL statement is blocked. The following describes the common diagnostic methods: suppose there is A table: table t (id int primary key,

Introduction to the advantages and disadvantages of Oracle Database indexes the following articles mainly introduce the advantages and disadvantages of Oracle Database indexes. We all know that Oracle Database indexes can be divided into clustered

Oracle Tablespace and data file management [html] Database model Database tablespace Datafile Segment Extent Oracle Block OS block create Tablespace SQL> create tablespace user_data 2 datafile 'd: \ userdata \ userdata1.dbf 'size 100 m 3; The

Oracle table unlocking method 1. obtain the sid. The serial parameter used to unlock select s. username, s. osuser, s. sid, s. serial #, p. spid from v $ session s, v $ process pwhere s. paddr = p. addr and s. username is not null; select 'alter