Add Constraints
SQL> alter table customer add constraint cardunique unique (cardId );
Delete Constraints
SQL> alter table customer drop constraint addresscheck;
When deleting a primary key, the cascade option must be included.
SQL> alter table
And, or, not:
1. a and B (sequential execution)
(1) true if a and B are the same as true,
(2) a, B, and false are false,
[1] If expression a is false, there is no need to judge later. The entire expression must be false;
[2] if a is true, the
1. about connecting to the Oracle database
①, Normally connected to generate the database
Of course, you must connect to Oracle before creating a database.
1. First select the DataBase type: DataBase ---> Choose DataBase:
2. Establish a connection:
This article is a collection of online articles and self-written operations, because there are many problems during the installation process, and it is not as smooth as it is written by others on the Internet, oracle official documentation is the
To better understand the differences between the 10gR2 RAC and the latest version, we will continue to build a 10gR2 RAC on the platform with the Environment configured in 11gR2.
Before installation, you must modify a Kernel Parameter of RHEL5.5 to
When startup is runningOracle error, ORA-600 error. The error is as follows,ORA-00600: Internal error code, parameter: [keltnfy-ldmInit], [46], [1], [], [], [], [], [], []
This error occurs when nomount is started, so it is related to the system.I
Description: The structure of table ta and table tb is identical. To update table ta with data in table tb,
Requirements: Take the ta as the standard. If the ta does not have data, the data in the tb is fully merged into the ta;
If the data in ta
-- Start service
1. telnet *. * username/password
-- Telnet to connect to the database server (or other connection services and tools such as SSH)
2. sqlplus/nolog
-- Use SQLPLUS Tool
3. connect/as sysdba;
-- Connection Library
4. startup;
--
Linux installation Oracle Reports Checking operating system version must be RedHat-3, SUSE-9, redhat-4, UnitedLin:
In the process of installing oralce in Linux, if the Linux release version is not the recommended version of oracle, the following
DML (Data Manipulation Language) is a Data Manipulation Language, one of the types of SQL, in addition to the Data Definition Language (DDL) Data Definition Language and Data Control Language (DCL) Data Control Language. DML includes INSERT, UPDATE,
When a user remotely connects to the MySQL database, the connection may fail because of the following reasons:
(1) the lowest possible cause-the network is disconnected. Including physical connection failure, network disconnection, and other
/* Obtain the pinyin corresponding to the name of the Oracle function */
Create or replace function F_GET_PY (V_XM varchar) RETURN VARCHAR2 ISS_py varchar2 (100 );Z_hz varchar2 (2 );Z_py varchar2 (10 );I number (3 );I _jls number (5 );BEGINS_py: = ''
Previously, the RAC platform was installed on two nodes. The database version is 10.2.0.1. The purpose of this experiment is to upgrade the database version from 10.2.0.1 to 10.2.0.4. The upgrade package can be downloaded from Oracle metalink. This
First, let's talk about basic operations. This is not related to java. It only talks about mysql operations, but also about Windows operations, which are roughly the same in linux.
1. If mysqldump is used, you need to install the mysql server. If
If you cannot create an Oracle table, log on to the server and check it. I tried to create a table, prompting you That the tablespace is insufficient. If you want to expand the tablespace, you will be OK, the following two errors are reported:
ORA-0
For a small etl scheduling, colleagues need to return the execution status of the stored procedure and control whether the subsequent dependency is executed, I only returned the output parameters of the stored procedure in the shell script that
Management notes for Oracle partition tables (only for common tables, that is, partition management for heap tables. IOT and cluster table are no longer discussed)
1. add partition)Syntax: alter table xxx add partition...It should be noted that if
SQL tuning focuses on the filter information. The developer sends an email asking me to optimize the following SQL
Hi Robinson,
Kindly need your help to check the below SQL for performance issue with Hyper plan detail report. Thanks in advance.
The lock mechanism is used to manage concurrent access to shared resources.
In Oracle, the transaction should be committed at the appropriate time, because the transaction is very long or very large, generally there is no pressure on the system; row-
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