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Oracle self study notes sorting (IV) 8, Functions 8.1 distinct When the keyword DISTINCT is followed by only one column 1, it represents the non duplicate data of the query result of a single field. When it is followed by multiple column values, it represents all the unique values of the query result composed of multiple fields, and the group ...

summary: Overview of information technology Principle of computer composition Computer software Mobile communication internet Digital media and its application Computer information system Definition: data intensive, man-machine interactive computer system with the main purpose of providing information services Features: large quantity, l ...

I Single-Row Functions Note: dual is a virtual table and cannot save any data. There is only one field and one row of records 1. Semantics The single line function returns a result for each record 2. Character function 1.lower(): convert to lowercase, upper(): convert to uppercase, initcap initial capital select lower(ename) from emp; 2 ...

  catalogue Create a process to raise 100 yuan for the designated employee. And output the wages before and after the rise. Query the name and salary of the specified employee, and use the out mode parameter value to pass it to the caller. Call by binding variables in the command window, and the related steps Create a stored procedure, que ...

oracle knowledge points summary Indexes Create index CREATE [UNIQUE] | [BITMAP] INDEX index_name --unique Represents a unique index ON table_name([column1 [ASC|DESC],column2 --bitmap，create bitmap index [ASC|DESC],...] | [express]) [TABLESPACE tablespace_name] [PCTFREE n1] --Specifies that the index has ...

1, Explain This installation will use Oracle universal installer (OUI) to install Oracle database software and database 1.1 Oracle operating system requirements under Linux Oracle Linux 8.1 with the Unbreakable Enterprise Kernel 6: 5.4.17-2011.0.7.el8uek.x86_64 or later Oracle Linux 8 with the Red Hat Compatible kernel: 4.18.0-80.el8.x86_64 ...

Similar articles OGG has both the traditional classic architecture and the latest microservices. Both of them can remotely capture and apply data and zero intrusion to the database server. The traditional classic architecture is a pure command-line mode. The latest microservice architecture is a graphical interface operation, and almost all op ...

The client's Linux system is already installed and the company has no DBA and has to go on its own. This article uses for reference: https://www.cnblogs.com/binghe001/p/12950804.html 1. Download installation files   Baidu Netdisk: https://pan.baidu.com/s/1ec-k9ShBg7O91YPAAhJ6mA Extraction Code: rba4 2. Close the firewall Operating user:ro ...

preface Continued [ORACLE] qualified expression of version 18c and its enhancement in version 21c At the end of the previous article, we talked about iterators. Because there are too many contents, they are put together with this article. In the iterator, in addition to the three iterators mentioned above (basic, index and sequence), it also ...

Author: threedaymanSource: Hang Seng LIGHT cloud communityBasic conceptsdatabaseoracle database is the physical storage of data. Including data file ORA or DBF, control file, online file, log file and parameter file. oracle has only one database, which is managed by users. The process of creating a database in mysql database is to create a data ...