SQL plays an important role in data analysis. When we are analyzing more number of records, we summarize the data and then analyse it. We do lot of ETL tasks to extract the data from data base and clean and format the data. Once we are created a clean data set, we go for analyzing the data to get more insights from the data.
What is SQL?
SQL stands for Structured Query Language which is a computer language for storing, manipulating and retrieving data stored in relational database. SQL is the standard language for Relation Database System. All relational database management systems like MySQL, MS Access, SQL Server, Oracle, Sybase, Informix, DB2 and other database systems uses SQL as standard database language.
Also they are using different dialects, Such as:
- MS SQL Server using T-SQL
- Oracle using PL/SQL
- MS Access version of SQL is called JET SQL (native format ), etc…
However, they all support at least the major commands (like SELECT, UPDATE, DELETE, INSERT, WHERE) to be compliant with the ANSI standard.
Why SQL?
- Allow users to access data in relational database management systems
- Allow users to describe the data
- Allow users to define the data in database and manipulate that data. For example, inserting records,updating or deleting records
- Allow users to create and drop databases and tables
- Allow users to create view, stored procedure, functions in a database
- Allow users to set permissions on tables, procedures, and views
Topics
- Basics of Database:
RDBMS stands for Relational Database Management System. A Relational database management system (RDBMS) is a database management system (DBMS). - SQL Statements:
SQL use the term query as the name for its commands. Basically, all SQL code is written in the form of a query statement and then executed against a database. - SQL Arithmetic Operators:
Arithmetic Operators, Comparison Operators, Logical Operators and Wildcard Operators helps Analysts while extracting and summarizing the data for analysis. - SQL Commands(dml, ddl, dcl ,tcl) for Data Analysis:
SQL Commands(dml, ddl, dcl ,tcl) help Analyst to create database,tables, views, update data. Also help to fetch the data and summarize to perform analysis. - SQL Functions for Data Analysis:
SQL functions help to aggregate the data while extracting the data from Data base. There are many functions available in SQL to aggregate the data. - Sorting and Grouping in SQL or ORDER BY and GROUP BY Clauses:
We can sort and group the data based on certain variables/ columns and understand the data., we use Order By, Group by helps to Sort and Ggroup data in SQL.
