Intro to SQL: Basic

SQL

SQL stands for Structured Query Language, this is a standard computer language for relational database management. SQL is used for data definition and data manipulation.

Pronounced as “Sequel” or “S-Q-L"

SQL used to communicate with the database and its statements are made up of descriptive words and are easy to learn

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What is Data Definition in SQL?

Data Definition is also very often used as a Data Description that means, Data Description in SQL statements to define how to store data in the columns of a table, how to present the data in the results of queries, and whether to apply column-level integrity constraints. SQL is used as a Data Definition Language (DDL).

What is Data Manipulation in SQL?

Data manipulation is another part of SQL which includes: Create or insert new data, update existing data, remove existing data etc. So, in this part SQL is used as a Data Manipulation Language (DML).

Features and Usage of SQL

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SQL is a non-procedural language. So, you cannot able to write a complete applications. but this is very Simple and powerful language for data definition and data manipulation.

SQL is all about data! It’s working with:

• Read/retrieve data from a database
• Write/insert data to a database
• Update/Modify any existing data to a database

SQL usage a board range of roles in the industry:

• Backend Engineer
• QA Engineer
• Database Admin (DBA)
• System Admin
• System Engineer
• Data Analyst
• Data Architect
• ETL Developer (Data Engineer)
• Data Scientist
• Business Analyst

How SQL used by a DBA and a Data Scientist

• Manage and Governs the entire database
• Gives permission to users
• Determines access to data
• Manages and creates new tables
• Uses SQL to query and retrieve data
• End-user of a database
• Uses SQL to query and retrieve data

How do Data Scientists Use SQL?

• Retrieve data
• May create their own table or test environment
• Combine multiple sources together
• Write complex queries for analysis

SQL and Database Management System (DBMS)

How you write syntax will depend on what DBMS tools are you using. Each DBMS tools has its own “dialect” and basically:

• SQL can translate
• You will tweak based on the “dialect” your DBMS speaks

Popular Relational DBMS services:

• Microsoft SQL Server
  

• MySQL
  

• Oracle PL/SQL
  

• PostgreSQL

• SQLite

• IBM DB2

Credit

• Cover Photo by Myriam Jessier on Unsplash

Conclusion

SQL is a very simple and powerful language for working with data that help us create, insert, update, delete, retrieve data from databases. on the next few articles we will learn more about SQL in details. thanks for learning.