SQL is a database language that is used to create, delete and manipulate databases. SQL stands for Structured Query Language. It supports Relational databases.
Dialects of SQL:
- Microsoft SQL Server using SQL as T-SQL
- Oracle using SQL as PL/SQL
- Microsoft Access using as SQL as JET SQL
Advantages of SQL:
- Access data of any relational database
- SQL Can be embedded in other programming languages
- SQL Can create, manipulate, delete any relational database
- SQL Can create views, functions and stored procedures
- Also settings of permissions on tables, procedures, and views
- SQL is Easy to learn and has high speed
- SQL can be used on any platform like Desktop, mobile etc
Applications of SQL:
- SQL is useful in writing Data Integration Scripts.
- SQL is used in Data Analytics.
- SQL can be useful in retrieving data.
SQL Process:
The following figure shows how SQL query is used to access data of a Relational Database.
The process involves the following four components:
- Query dispatcher
- Optimization engines
- Classic Query Engine
- SQL Query Engine
First, the query is processed by Query engine and optimization engine tries to optimize it and improve the performance. Then the optimized query is used by the database engine to access data of the relational database.