As we know to write a simple program, we need to have knowledge of a programming language. Similarly, in database management systems, to extract or work on the data on the database we need to know some languages. These languages are called Database Languages.
These languages allow the users to control the data and perform operations like inserting, deleting, modifying, or extracting data from database tables.
Database languages are divided into four types on the basis of the kind of operations they perform –
4 Categories of Database Languages
1. Data Definition Languages (DDL)
Data Definition language also known by its short form DDL is used to create the structure of the database. It is used to create and alter the attributes and records within the table.
Also, it includes operations like renaming or dropping the existing components of the database.
Given below is the list of DDL statements –
Create – Creating the table, index, or column in a database.
Alter – Change the structure of the database or its components.
Drop – Deletes the table or its objects.
Truncate – used to mark the extent of a table for deallocation (empty for reuse)
Rename – used to change the name of an existing database object(like Table, Column) to a new name.
2. Data Manipulation Languages (DML)
Data Manipulation Language also known by its short form DML provides a way to access and manipulate data stored within the database. It includes operations such as inserting, extracting, or updating the data within the database.
Select – Retrieves data from the tables.
Insert – Insert data into the table.
Update – Modify the records of the table.
Delete – Delete the records from the table.
Merge – insert new records or modify existing records depending upon whether condition matches.
3. Data Control Language
Data Control Language also known by its short form DCL controls user permissions. It basically controls the rights and permissions to access the data by the user. Their permissions are given by the Database Administrator. Given below are the Data Control Language statements –
Grant – allow the users to access the database.
Revoke – Remove access to the database from a user.
4. Transaction Control Language
Transaction Control Language manages the transaction within the database.
These are used to manage the changes by the statements within the Data Manipulation Language.
Commit – Carries out a transaction successfully.
Rollback – Restores the transaction if the transaction fails.
Savepoint – Set a savepoint in a transaction.
So, in this article, we learned about the four different categories of DBMS languages and also some statements that are used within these languages. To work on a database, one must have good knowledge about the commands within each of these languages so that he can have control over the data stored in these tables.
You may also like to read: Data Structures Tutorials
Also, attempt the free DBMS Practice Test
