Skip to main content

Posts

Showing posts from September, 2020

Dual Table in Oracle and its uses in Database #Diksha Oracle Training Centre

  Dual Table in Oracle and its uses in Database. Hello Everyone, Today we will discuss about Dual table in Oracle and it’s benefit in Database.Dual table in Oracle which is a special and dynamic table used for evaluating expressions or calling functions. Once you Install Oracle Database in your System Dual table is available in all schema’s . The DUAL table contains one column named DUMMY whose data type is VARCHAR2() and contains one row with a value X. The DUAL table is most simple one because it was designed for fast access and can be used for any calculation checking date and printing any value as the output for our  requirement. To  Access Dual table we can use Select statement. To see the output from Dual table we can use below select statement and can see output as column DUMMY with one Row value X. Select *  from dual; By using the DUAL table, we can execute queries that contain functions that do not involve any table like the UPPER() function as be...

SQL Joins and its importance in Oracle Database #Diksha Oracle Training Centre

  SQL Joins and its importance in Oracle Database.     Hello Everyone, Today I will discuss why SQL Joins is important in any database , Before starting Join please go through my below blogs so it’s easy for you to write different types of Joins . https://dikshaoracletraining.blogspot.com/2020/09/sql-and-classification-of-sql-in-oracle.html https://dikshaoracletraining.blogspot.com/2020/09/basic-sql-commands-in-oracle-database.html Why Join is important: The SQL Joins clause is used to combine records from two or more tables in a database. A JOIN is a means for combining fields from two tables by using values common to each. Join used to match rows between tables. In most cases we're matching a column value from one table with another. So In Simple word we can say Joins is basically used to get the data from one or more tables to get the required data and Joins can be of different types which can be used for trend analysis in any organization. Let’s Understand...

Basic SQL Commands in Oracle Database #Diksha Oracle Training Centre

  Basic SQL Commands in Oracle Database.   Hello Everyone, In my previous blog I discussed about SQL and Classification of SQL . Today I will discuss about SQL basic commands which widely used in RDBMS. The Topics of SQL command which I am going to cover in this blog are mainly divided into four Categories: ·         DDL:   DDL consists of commands which are used to define and design the database. ·         DML:   DML consists of commands which are mainly used to manipulate the data in the database. ·        DCL: DCL Consists of commands which deal with the user permissions/access and controls in the database. ·       TCL:   TCL Consist of commands which deal with the transaction in the database. If you want to explore theory part please follow my below blog as in today blog I will discuss about how to use the commands. h...

SQL and Classification of SQL in Oracle Database #Diksha Oracle Training Centre

  SQL and Classification of SQL in Oracle Database.   SQL is Structured Query Language , which is used for storing, manipulating and retrieving data stored in a relational database .SQL is the standard language for RDBMS. All the Relational Database Management Systems (RDMS) like Oracle, MySQL, Sybase, Informix, IBM DB2 and Microsoft SQL Server use SQL as their standard database language. Oracle is one of the more secured database as compared to other databases. Importance of   SQL : SQL and PL/SQL is a backend process where all data is stored and retrieved in GUI which created either by any programming languages like Java, C++, PHP etc. so we need to have very secure database so that there will be no impact for users. SQL allows users to access data in the relational database management systems. SQL is used to communicate with a database.SQL and PL/SQL allows users to create and drop databases tables , views , stored procedures , functions , packages , trigger et...