To be a good Data Scientist, you should have some knowledge about SQL. Many beginners who are trying to get into Data Science but, worried about coding, they start with SQL queries. After that, you have to learn either Python or R to learn and apply Data Science. In this blog post, firstly I am going to describe what is SQL and then, how SQL can help you to get started with Data Science.
What is SQL?
SQL (pronounced as Sequel) is a Structured Query Language. That is to say; it is a programming language, designed to manipulate data that is stored in a Relational Database Management Systems or RDBMS. It is used to insert, delete, update, modify data, etc. Remember, SQL can not write full applications. Data Scientists are using SQL to fetch the data from databases. After that, they apply some magical kinds of stuff on the data. SQL is very simple to learn, but, it is a very powerful language.
How does SQL works?
SQL work in a very simple way. It is a Query Language, that is designed to retrieve information from databases.
SELECT * FROM table_name;
Here SELECT * refers that we have to select all the columns and FROM table_name refers from that table_name.
In english it is like, Select all the column or all the fields from table_name. For example, look at the below qureies.
SELECT States FROM Country;
It refers that, Select all the information on States column from the table Country.
SQL queries are case-insensitive in other words, SELECT is same as select. Likewise, FROM is same as from.
What is DBMS?
A database is an organized collection of structured data. Database Management Systems or DBMS is software for storing and retrieving data in a simple organized way. There are many SQL servers available, so, as a data scientist, you have to familiar with one of them at least. The server depends on the company you are working for, in addition, the syntax may change a little bit based on the DBMS you are using.
SQL is a bridge between You(Data Scientist) and the database. Some polpular SQL servers are –
How do Data Scientists use SQL?
We know that the most important thing to a data scientist is data. Data may come from many sources. Data scientists may need to create their own database and then, they might store information or delete information from that. We need SQL to retrieve data from databases. After that, some data cleaning process takes place. And then subsequently, applying Machine Learning Models, training, testing, predicting, visualizing all the steps take place.
SQL for Data Scientists
If you want to start your career in Data Science, then it will be great, if you start with basic SQL. So, here I have listed top SQL courses, in addition, some Data Science Courses as well, please check them out.
Top SQL Courses for Data Scientists
- Master SQL For Data Science
- SQL & Database Design A-Z™: Learn MS SQL Server + PostgreSQL
- SQL for Data Science
- Microsoft Access SQL: SQL for Non-Programmers