Introduction to SQL

Introduction to SQL

In this article, I am going to give you a brief introduction to SQL. SQL stands for Structured Query Language. At the end of this article, you will understand the following pointers in detail.

  1. What is SQL?
  2. Who should learn SQL?
  3. History of SQL
  4. Advantages and Disadvantages  of SQL
  5. What is Excel?
  6. Advantages and Disadvantages  of Excel
  7. SQL vs Excel
  8. What is MySQL?
  9. Difference Between SQL and MySQL
  10. Why we need MySQL?
  11. What is Oracle?
  12. Difference Between MySQL and Oracle
  13. What is DBMS?
  14. What is RDBMS?
  15. Difference between Database Engine, Database Server, and Database Software
What is SQL?

SQL may be a language to work databases; it includes database creation, deletion, fetching rows, modifying rows, etc. SQL is an American National Standards Institute (ANSI) standard language, but there are many different versions of the SQL language. SQL is a Structured query language, which can be a computer language for storing, manipulating, and retrieving data stored during an on-line database.

SQL is that the standard language for electronic database Systems. All the electronic database Management Systems (RDMS) use SQL as their standard database language. SQL is that the quality language for handling Relational Databases. SQL used to insert, search, update and delete database records. SQL can do many other operations like optimizing and maintenance of databases.

Who should learn SQL?
  1. Are you a student who wants to find out SQL for your academic purpose? Then yes! you’ll follow alongside this course and learn SQL.
  2. If you’re an internet designer or an internet developer and you’re looking to develop a database-driven website or web application. Then Yes! this course is for you.
  3. By learning SQL (Structured Query language), you’ll be ready to find out how the database system works. you’ll get conversant in RDMS electronic database management system and also the way to use various SQL syntax to manage your database for your web applications.
  4. Likewise, web developer’s desktop and mobile application developers also require to use databases for his or her applications. By learning SQL you’ll be ready to work with any database software that uses structured command language.
  5. Databases also are utilized in network applications. So even you’re a network application developer learning SQL is useful for you.
  6. In short, SQL is often implemented in any application development that uses databases, and every major database software uses structured command language.
History of SQL

SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce within the early 1970s. The programming language was named SEQUEL at the time when it had been developed. In June 1979, Relational Software Inc. introduced the primary commercially available implementation of SQL, Oracle V2 (Version2) for VAX computers.

Basic Concepts of SQL
  1. SQL stands for Structured command language.
  2. SQL is a standard language for accessing and manipulating databases.
  3. The user can issue a question when he/she wants to retrieve information from a database.
  4. A query may be a user-generated request to retrieve data or a set of data with a particular condition.
Categories of SQL

SQL functions fit into three broad categories:

  1. Data definition language (DDL) deals with database schemas and descriptions. It includes different commands like create, alter, drop, truncate, comment, rename, etc.
  2. Data Manipulation Language (DML) deals with data manipulation. It includes different commands like select, insert, update, delete, merge, etc.
  3. Data Control Language (DCL) deals with the rights and permissions of the database system. It includes commands like grant and revoke.
Advantages of SQL
  1. SQL Queries are often wont to retrieve large amounts of records from a database quickly and efficiently.
  2. Using standard SQL, it’s easier to manage database systems without having to write down a substantial amount of code.
  3. SQL databases use long-established standards which are being adopted by ANSI & ISO.
Disadvantages of SQL
  1. Difficulty in Interfacing: Interfacing an SQL database is more complex than adding a couple of lines of code.
  2. More Features Implemented in Proprietary way: Although SQL databases conform to ANSI & ISO standards, some databases choose proprietary extensions to plain SQL to make sure vendor lock-in.
What is Excel?

Microsoft Excel is an application that wants to build and format spreadsheets. it’s good for operations on flat files – summarizing, cross-validating, visualizing and building pivot tables. it’s a really powerful application that has the power to try to do many things like calculating loans, etc.

Advantages of Excel
  1. It’s easy to browse data.
  2. It’s easy to manually enter and edit data.
  3. Formulas make it a living document.
  4. It features a built-in suite of helpers for charts, comments, spells checking, etc.
  5. It’s relatively easy to find out.
Disadvantages of Excel
  1. It isn’t suitable for working with multiple datasets together.
  2. Lacks data integrity.
  3. It doesn’t scale. because the amount of knowledge increases, performance suffers.
  4. If you’ve got two people editing data in Excel, you’ll expect three copies of the ultimate spreadsheet.
  5. It uses a bunch of filters and sorting for locating some data during a spreadsheet.
SQL vs Excel
  1. If you would like to figure with tons of knowledge, you’ll roll in the hay with one or two commands. you do not get to worry about skipping the last row or having one incorrect formula out of 1,000.
  2. For searching some data, you’ll roll in the hay with one query rather than employing a bunch of filters and sorts or a manual selection in the database.
  3. If you’ve got two people editing data in Excel, you’ll expect three copies of the ultimate spreadsheet. this is often manageable with touch data, but it becomes time-consuming and error-prone with more. Databases are designed to handle multiple users.
  4. Even if you’re just storing data, Excel features a hard limit of 1 million rows per sheet. an honest database will store and process the maximum amount of data your disk drive can hold.
What is MySQL?

It is the combination of My and SQL, MySQL. It is open-source software. MySQL may be a management system that permits you to manage relational databases. It is open-source software backed by Oracle. It means use MySQL without paying a dime. We can also change its ASCII text file to fit your needs. MySQL is easy as compared to other database software like Oracle Database, or Microsoft SQL Server. MySQL can run on different platforms like UNIX, Linux, Windows, etc. You can install it on a desktop or even on a server. MySQL is a reliable, scalable, and fast database.

Difference Between SQL and MySQL
  1. SQL is a database language whereas MYSQL is software.
  2. SQL is used for storing, manipulating, and retrieving data in a relational database whereas MySQL is an open-source Relational Database Management System that allows us to manage relational databases.
  3. SQL helps us to manage the data in the relational database whereas MySQL helps us to manage relational databases using SQL.
  4. SQL does not change as it is a language whereas MySQL updates as it is software.
Why we need MySQL?
  1. It is secure because it uses solid data security to protect sensitive data.
  2. It manages memory well and prevents memory leaks.
  3. It is fast as compared to other databases like Oracle.
  4. It is scalable which can handle a total file size of about 4GB.
  5. It is not expensive to use and maintain MySQL.
What is Oracle?

An Oracle database is a collection of data treated as a unit. The purpose of a database is to store and retrieve related information. Oracle Database is the first database designed for enterprise grid computing, the most flexible and cost-effective way to manage information and applications. Enterprise grid computing used to create large pools of industry-standard, modular storage, and servers. With this architecture, each new system can be rapidly provisioned from the pool of components. There is no need for peak workloads because capacity can be easily added or reallocated from the resource pools as needed.

Difference Between MySQL and Oracle
  1. MySQL is open-source whereas Oracle is commercial.
  2. MySQL is a relational database management system whereas Oracle is a multi-model database management system.
  3. MySQL only works with static systems whereas Oracle works with both dynamic and static systems.
  4. MySQL allocates each privilege separately whereas Oracle has allocated and denied from users together.
  5. MySQL permits null value whereas Oracle does not permit null value.
What is DBMS?

The full form of DBMS is Database Management System. DBMS is a program by using it you can interact with the databases to store, modify and extract the data. In other words, A database management system is a program or system software for creating and managing databases. The database serves as an interface between the database and application programs or users. The DBMS gives applications and users a systematic way to create, read, update and manage the data.

The DBMS manages 3 important things: –

  1. The data
  2. The database engines (database engine is a system for storing and retrieving data)
  3. The database schema (database logical structure).

There are mainly 5 types of database management systems: –

  1. RDBMS: Relationship database management system.
  3. In-memory database management systems. (IMDBMS)
  4. Columnar database management system (CDBMS)
  5. Cloud-based database management system

Note: In this course, we will mainly focus on the relational database management system that is RDBMS. The most popular database management systems are MYSQL, Oracle, SQL Server by Microsoft, PostgreSQL, and IBM DB2.

What is RDBMS?

The full form of RDBMS is a relational database management system. A relational database management system (RDBMS) is nothing but a database management system (DBMS) that is used to manage a relational database. And a relational database is the database that follows the relational model as invented by E.F. Codd. It is the basis for SQL and all modern database systems which store data in the form of related tables. In RDBMS, a single database can be spread across several tables.

Difference between Database Engine, Database Server, and Database Software.
Database Software

Database Software is also known as database management systems (DBMS). Database software is a computer software application that serves as an interface between the database and application programs or users. The most popular Database software are MySQL, Oracle, SQL Server by Microsoft, PostgreSQL, and IBM DB2. In this course we will work on a database software or database management system, that is MySQL.

Database Engine

A database engine is also known as a storage Engine. Database Engine is the part of a database management system (DBMS) that actually stores and retrieves data. In other words, Database Engine is an underlying software component used by database management systems (DBMS) to create, read, update and delete (CRUD) data from a database. Many of the modern database management systems support multiple storage engines within the same database.

Database Server

A database server is a program that provides database services to other computer programs or computers using a client-server architecture. The database server may also refer to a computer dedicated to running such a program. Some databases like MySQL completely depend on the client-server model for database access.

In the next article, I am going to show you how to download and install the MySQL database for development. In this article, I try to give a brief introduction to SQL and I hope you enjoy this article.

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