Overview of SQL using Oracle Database 19c
SQL stands for Structured Query Language and is a very powerful non-procedural language. SQL is a standardized language and used in all RDBMS. SQL is mainly important for analyzing and understanding the databases that contain all the necessary information stacked in them.
SQL was originally developed at IBM’s San Jose Research Laboratory. Initially, it was called SEQUEL (Structured English Query Language) but later needed to change its name because another business claimed that name as a trademark. Afterwhile, SEQUEL is renamed to SQL and has turned into an official standard for the ANSI (American National Standards Institute) and ISO (International Organization for Standardization).
Why SQL is important and why should you learn SQL?
1. SQL is the most universal and commonly accepted database language
We live in an era which is well known as the Information age. Data is the most valuable asset and it’s the heart of every decision making process. Despite of the explosion of NoSQL in the recent years, SQL is still the universal interface for data access, manipulation and analysis.
2. SQL is not really difficult to learn
SQL is not a programming language, it’s a query language. The primary objective of SQL when created was to give the possibility to common people get interested in data from database.
SQL is an English like language so anyone who use English at a basic level can write SQL query easily. Most RDBMS are compatible with SQL, and so, once you learn SQL it should be similar to work across any relational databases.
3. SQL programmers have demand always
You shouldn’t have a problem finding a job as a SQL programmer/ database developer. This is because, database is widely used across the world and corporate sectors at least need developers who can mange their business databases.
Features of Oracle SQL?
1. SQL is a standardized language and used in all RDBMS. Although most RDBMS use SQL, most of them also have their own additional proprietary extensions and hence the syntax of SQL changes very little from one RDBMS to another.
2. SQL is a non-procedural language which means you have to specify what to do, rather than how to do the task. How the task should be done is the responsibility of the underlying RDBMS. On the contrary, in a procedural language, you have to give the complete procedure of doing the task. Oracle has PL/SQL which is a procedural language extension to SQL.
3. SQL is not case-sensitive which means keywords are case insensitive in Oracle. But data within a database table is case sensitive.
What you must know as a database developer?
- You need to know how to implement the specified functions for accessing and manipulating the application data.
- You need to know how to implement the rules for data integrity.
- You need to know how to implement the data model that the application requires.
Tools to access Oracle Database
You must remember that you can access an Oracle Database only through a client program, and that the SQL language is that client program’s interface to the Oracle Database.
You will learn how to access the Oracle Database by using two clients that are packaged with the Oracle Database and designed for developers: SQL Developer and SQL*Plus. Both allow you to issue the SQL statements you need in order to create and test your application’s database component without doing any client programming.