Hello World of plsql
set serveroutput on
--Print Hello World
--Explanation section(Variable, cursor or exception description)
--Program body ( DML Statement)
Use of basic variable types
-- Use basic variable types
--Define basic variable types ...
There is a bug in the previously designed tranform, which can be solved by raising the limit, so learn the rules raised on calculate. By the way, it also lays a foundation for the elimination of public expressions later.
What did you do?
It is not difficult to see from the name that the constant ...
Posted by pk-uk on Tue, 01 Feb 2022 03:15:11 +0100
1, Basic knowledge
1. Role of backup and restore:
Backup mainly plays the role of data disaster recovery. It is an effective means to ensure data security in case of database failure; By restoring the backup set data, the data can be restored to the state before the database failure.
2. Basic principles of backup, restore and recovery:
In D ...
Posted by mlschutz on Thu, 27 Jan 2022 08:28:35 +0100
1.1 PrimaryKey(PK): primary key Features: unique + non empty, a table can only have one primary key constraint It is usually a numeric column Better be meaningless
1.2 NOT NULL Features: cannot be empty. We recommend that the business key column (index column) be set as non empty as possible
1.3 UNIQUE constraint Features: ...
Posted by epetoke on Mon, 24 Jan 2022 17:39:59 +0100
Introduction to the Author
Author: Lucifer Liu, member of the Chinese DBA Consortium (ACDU).Currently mainly engaged in Oracle DBA work, has been engaged in Oracle database development work, mainly serving the production and manufacturing, Automotive Finance and other industries.Now has Oracle OCP, OceanBase OBCA certification, good at Orac ...
Posted by DGaleDavid on Mon, 17 Jan 2022 21:31:59 +0100
1, What is a Session
Session is an interface (HttpSession).A Session is a Session. It is a technology used to maintain an association between a client and a server.Each client has its own Session.In the Session session, we often use it to save the information after the user logs in.
2, How to create a Session and get (id number, new or not)
Posted by buildakicker on Fri, 14 Jan 2022 21:32:03 +0100
In work, we delete data or database by mistake. Do we have to run away? I don't think so. Programmers must learn to save themselves and retrieve the data unconsciously.
In MySQL database, we know that binlog logs record all our operations on the database, so binlog logs are a sharp tool for us to save ourselves.
Today, taking MySQL databa ...
Posted by tunari on Tue, 11 Jan 2022 03:48:29 +0100
Tip: after the article is written, the directory can be generated automatically. Please refer to the help document on the right for how to generate it
I saw it on the bus in the morning**_ The article on MySQL binlog written by yidianyu * * in Jiangnan is very detailed about the use of binlog to recover the database. I can under ...
Posted by cbolson on Fri, 31 Dec 2021 17:04:25 +0100
Please read carefully and refer to the README document for the latest steps, processes and related requirements for the overall upgrade of Oracle 19c rac cluster from 19.3 opatch to 19.10.
1, View the current database patch version
col ACTION for a8
col status for a15
set line 999
col ACTION_TIME for a30
col DESCRIPTION for a50
SQL> selec ...
Posted by dianaqt on Thu, 30 Dec 2021 18:40:19 +0100
The DBLINK built this time is to access the SQL SERVER database on the Win side of the Damon database on the Linux side. By configuring ODBC to connect to the SQL SERVER database, DM creates an ODBC DBLINK connection to realize the DBLINK between DM and SQL SERVER. The following are the specific operation steps.
DBLINK (Datab ...
Posted by Dustin013 on Thu, 23 Dec 2021 18:52:15 +0100