SQL Tutorial

SQL Stands for Structured Query Language. It is a language created to work on Relational Databases.
A Relational Database is a type of database, where data is stored in the form of tables with relations between the tables.
The language can be used for the following operations.

Querying Database with filters.
Inserting new records into tables.
Updating existing records into tables.
Delete records from table.
Create database schema, table structure
Alter database schema and table structure
Delete database schema and tables
Configure permissions for various database objects

SQL was developed at IBM by Donald D. Chamberlin and Raymond F. Boyce in 1970s.
SQL is sometimes pronounced as SEQUEL.

SQL Syntax:

SELECT * from Customer WHERE Customer_Name = "Jack Sparrow"

The Major parts of a basic SQL Statement are:

1. Clauses
Clause is component of statement or queries.

SELECT *

Above example shows a SELECT clause.
There are other clauses like WHERE, UPDATE etc which we will see through these tutorials.

2. Expressions

Expressions are logical statements which are executed against the clause.

Customer_Name = "Jack Sparrow"

Above example shows expression where we are Checking if Customer_Name is "Jack_Sparrow".

3. Queries

Queries are used to retrieve data based on specific criteria. Example Query we saw in the example.

SELECT * from Customer WHERE Customer_Name = "Jack Sparrow"

We only get data for the Customer whose name is "Jack Sparrow".