Structured Query Language, full form of SQL is a standard Database language which is used to carry out different operations in a database. It is a language by which we can create, maintain and retrieve the relational database. SQL operates based on relational algebra and tuple relational calculus. With the help of SQL, we can create, delete the database, fetch rows and modify them. To perform SQL queries, you need to install a database like Oracle, MySQL, MongoDB, PostGre SQL, SQL Server, DB2, etc.
SQL Full Form | What is the full form of SQL?
In a database, the tables are broken up into smaller entities called field, which is the column of the table in simple words. A field is designed to maintain specific information stored in the rows of the table.
The SQL consists of 3 sublanguages which are used to manipulate and control the database. These are DDL (Data Definition Language), DML (Data Manipulation Language), DCL (Data Control Language).
DDL deals with database schemas and descriptions, of how the data should reside in the database. It includes the SQL commands like CREATE, ALTER, DROP, TRUNCATE, COMMENT, RENAME.
DML deals with data manipulation and it is used to store, modify, retrieve, delete and update data in a database. It includes most common SQL statements such as SELECT, INSERT, UPDATE, DELETE, etc.
DCL is concerned with permissions, rights and other controls of the database system. The commands used in this language are GRANT, REVOKE.
We can retrieve data from two different tables of the database with the help of SQL Joins (Left Join, Right Join, Inner Join, Outer Join). The basic SQL commands used are Create, Update, Alter, Select, Insert.
- Create command is used to create tables in the database.
- Update command is used to manipulate data in the stored in the tables of the database.
- Alter command is used to update the fields of the tables.
- Select command is used to recover data from the database.
- Insert command is used to insert data into the fields of the table.
The SQL contains some predefined arithmetic functions like max(), min(), count(), sum(), which returns the maximum, minimum values of the selected column, count of the unique fields and the sum of the data present in the field of the table respectively.
Advantages of SQL
- Structured Query Language, full form of SQL, is considered as an open-source programming language, hence it has a huge community of developers.
- Database technologies like MySQL, Microsoft SQL, PostgreSQL Server are used in many organizations like small companies, banks, hospitals, colleges.
- The portability feature of SQL makes it easy to be used in PCs, servers, laptops, and even some of the mobile phones.
Disadvantages of SQL
- Some users find difficulty in accessing the SQL interface.
- One cannot have full control over the database because of its hidden business rules.
- The Vendor lock-in feature in some databases used for a proprietary extension creates difficulty for some users.