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Oracle constraint belongs to an object of database In order to facilitate the maintenance of constraints, Oracle saves all constraints as independent database objects, and these information are also stored in the data dictionary, so each constraint needs its own noun to maintain. When the user does not set a name for the constraint, the sys ...

A major difficulty in migrating Oracle database to MySQL database is the replacement of the primary key generation strategy. If Oracle's Sequence mechanism is used in previous programs to achieve the primary key self-increment, it is necessary to use TableGenerator for equivalent replacement in MySQL. When replacing, there are three main area ...

How to achieve id self-growth after inserting data Reference Blog: http://www.cnblogs.com/hyzhou/archive/2012/04/12/2444158.html ORACLE SEQUENCE Usage In oracle, sequence is the serial number, which increases automatically every time it is taken. Sequence has nothing to do with tables. 1,Create Sequence First, you need to have CREATE ...

This paper refers to: Le Shami's World For physically damaged data blocks, we can complete the recovery of damaged blocks through the RMAN Block Media Recovery (BLOCK MEDIA RECOVERY) function without requiring the whole recovery. data base Or all files to repair these small amounts of damaged data blocks. Restoring the entire database or ...

JDK Installation using PPA source mode: Add PPA sudo add-apt-repository ppa:webupd8team/java sudo apt-get update Install oracle-java-installer // JDK7 sudo apt-get install oracle-java7-installer // JDK8 sudo apt-get install oracle-java8-installer Installer will prompt you to agree to oracle's terms of service and select ok Then sel ...

multi-table query This article mainly talks about four points: (1) oracle multi-table query (2) join query of SQL99 standard (3) sub-query (4) hierarchical query There are two ways of Oracle multi-table query, one is oracle's unique query mode, the other is SQL99 standard join query, and it is a general multi-table query. 1. Oracle Connection E ...

From --------------------- http://blog.csdn.net/zwk626542417/article/details/39667999 origin   Today, as usual, landing PL/SQL did fail. An error "ORA-01034" and "ORA-27101" appeared as follows: Then it logs in through a command prompt. Oracle To see what's going on, and then the problem goes on, the e ...

1,Subquery 1.1,Introduction to Subqueries 1.2,WITH Subquery 2,Aggregate query 2.1,UNION and UNION ALL 2.2,MINUS 2.3,INTERSECT 2.4,Set Operations and ORDER BY 3,DISTINCT clause 3.1,General usage 3.2,Parameters for aggregation functions 4,summary 1. Subquery 1.1. Introduction to Subqueries A sub-query is a query nested in SE ...

Oracle's Basic Skills for Preluding PL/SQL Programming 1 > Write package specifications and packages, which contain stored procedures and functions. create or replace package emp_action_pkg is        v_deptno number(3):=20;        -----Define a process for adding employees        procedure newdept(                  p_deptno   dept.deptno%Ty ...

During the RECOVER restoration process of RMAN, the RMAN interface is normal, but the alarm log is checked and refreshed. It is found that there is ORA-279 in the alarm log, as follows:   alter database recover logfile '/u06/archivelog/2019_02_19/o1_mf_1_16228_g6oznpbv_.arc' Thu Feb 21 08:49:48 CST 2019 Media Recovery Log /u06/archivelog/2019_ ...