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A Short Guide to Oracle SQL [VI] – Scalar Functions and Regular Exp.

Oracle provides a wide range of built-in functions. These functions increased our ability to manipulate the information we retrieve using basic commands of SQL. A function, in general sense, can be seen as a block of code that accepts an arguments (sometimes not) and always return a output (a value). Oracle database offers wide rang … Continue reading

A Short Guide to Oracle SQL [V] – Joins & SET operators

In this part we talk about Joins and Set operations. JOIN Join operation combines rows from two or more tables/views/materialized views. Specifying multiple tables in FROM clause causes, Oracle to perform JOIN operation. Following example perform a simple JOIN operation. NOTE: If any of the table in join operation have common column name, the column … Continue reading

A Short Guide to Oracle SQL [IV] – More on SELECT

In the previous part we have talk about generally used DML statements and transaction control statements. Let’s begin this part with two clauses of SELECT statement WHERE clause and ORDER BY clause. But first let’s start with DUAL table and Pseudo-columns. DUAL table DUAL is a table which is created by oracle along with the … Continue reading