Oracle

There is an update without the insert (mysql,oracle)2018-02-011 OrcaleCreate TableTable1 (IDvarchar2( -)Primary Key, namevarchar2( +), Addressvarchar2( +));--executed two times, will be reported [ERR] ora-00001:unique constraint (PBOC. sys_c0014610)

A trigger (trigger) is a method that SQL Server provides to programmers and data analysts to ensure data integrity, which is a special stored procedure related to table events, which is executed either by a program call or by a manual startup, but

Although the ORM mapping is used in the project, the optimization of the Oracle system is very valuable, and here is a summary of the frequently used statements from the perspective of the SQL statement.1. Optimizations in the From field:Oracle

Official documents:home/database/oracle Database Online Documentation 11g Release 2 (11.2)/Database administrationEXISTS ConditionAn EXISTS condition tests for existence of rows in a subquery.The EXISTS condition tests whether rows exist in the

Test conditions:Suppose a company is headquartered in Beijing, Xinjiang has its subordinate branch. In this test, the computer in Xinjiang for the local computer, that is, the IP address is: 192.168.1.100Beijing's headquarters has a centralized

start and Close commandsOpen Servernet start OracleservicebinboOpen ListenerLsnrctl startStart the databaseStartupClose the databaseShutdownTurn off monitoringLsnrctl stopCreate a databaseDbcaCreate a listenerNetcaCREATE TABLE SpaceCreate tablespace

The Oracle database can also create temporary tables in addition to saving permanent tables. A temporary table is a nologging that is stored in a temporary table space and does not log.1. Temporary tables can create temporary indexes, views,

Explanation of nestedloops SEMI (SEMI-NESTED loop) in oracle execution plan, nestedloops InSubquerySQL statement and ExistenceEXISTSOfSQL statementThere is a nested loops semi (SEMI-NESTED loop) in the execution plan ). The so-calledNested loops

How Does Oracle select the parameter cache or nocache when creating a sequence ?, Sequencenocache How Does Oracle select the parameter cache or nocache when creating a sequence? The differences between the two are as follows: First, let's look at

How to Create tablespaces and users in oracle and create tables in oracle1. First, if a user exists Drop user username cascade; 2. if it cannot be deleted, the current user may be in the connection status. You can find the session Select username,

Oracle personnel permissions, string-to-column conversion, statistical management details, oracle details Use table Valued Functions 1. Create a type Create or replace type row_sys_user as object ( Userid int, Roleid varchar2 (500) ) 2. Create a

Oracle> Shell script for a single oracle instance [20180122], oracle-20180122The script is mainly used for redhat Platform Installation of 11g and 12c software dependent package check and installation of users, group check and installation of system

How can I obtain all the index creation statements in ORACLE ?, Oracle index creation statement How can I obtain all the index creation statements in ORACLE? Set pagesize 0 Sets long 90000 Set feedback off Set echo off Spool all_index. SQL SELECT

Check the maximum number of connections allowed by the oracle database and the current number of connections. Step 1: On the cmd command line, enter sqlplus Step 2: Enter the user name and password as prompted 1. view the processes and sessions

64-bit Oracle11g + LSQL Developer, win10oracle11g installed in win10 System As a powerful Oracle editing tool, LSQL Developer only supports 32 bits. This article provides how to enable 64bitOracle with LSQL Developer during installation.Tool/raw

Oracle Optimization Methods and Techniques1. Status Quo description Long SQL Execution time and slow Data Query 2. Problem object SQL statement execution (especially multi-Table multi-condition association query data) 3. Theoretical knowledge 1.

Flashback in oracle and oracleOverview: Flash back is part of Oracle's powerful Database Backup recovery mechanism. When a logical error occurs in the database, flash back technology provides fast and minimal recovery (most flash back functions can

Oracle Database basics: Table creation syntax and operations, oracle DatabaseSyntax 1. Create a table Create table Name ( Column name data type, ...... ); 2. delete a table: drop table name; 3. add a column: alter table name add (column name data

Solve the problem that Oracle11g cannot export empty tables. oracle11g exports empty tablesORACLE 11g export database file backup using the exp command, it is found that only a part of the table can be exported and no error is prompted, the solution

(Les02 Installation) [1, 20180118], les0220180118Learning target database administrator (DBA) task and tool Oracle software installation Oracle Grid Infrastructure installation Oracle DB Installation  Design, Implementation, and maintenance of