Database Language in DBMS

• A DBMS is software that used appropriate languages and interfaces to express database queries and updates.
• Database languages are used to read, store and update the data in the database.

 Types of Database Language 

1. Data Definition Language (DDL)

• Used to define database structure, skeleton, or pattern.
• It is used to create schema, tables, indexes, constraints, etc. in the database.
• Store the information of metadata like the number of tables and schemas, their names, indexes, columns in each table, constraints, etc.

DDL performs the following commands:-

• Create: It is used to create objects / database/ table/ view in the database with constraints.
• Alter: It is used to modify the structure and add column/constraints/remove the column from the table with help drop commands in the database.
• Drop: It is used to delete objects/tables and databases.
• Truncate: It is used to remove all records from a table and save table structure for reuse.
• Rename: It is used to rename an object.
• Comment: It is used to comment on the data dictionary.

 2. Data Manipulation Language (DML)

• Used for accessing and manipulating data in a database.
• It handles user requests.
• Some tasks of DML:

• Select: It is used to retrieve data from a database.
• Insert: It is used to insert data into a table.
• Update: It is used to update existing data within a table.
• Delete: It is used to delete all records from a table.

 

3. Data Control Language (DCL)

• Used to retrieve the stored or saved data.
• The DCL execution is transactional. It also has rollback parameters.

(But in Oracle database, the execution of data control language does not have the feature of rolling back.)

Here are some tasks that come under DCL:

• Grant: It is used to give user access privileges to a database.
• Revoke: It is used to take back permissions from the user.

 

4. Transaction Control Language (TCL)

• TCL is used for the changes by the DML statement.
• TCL can be grouped into logical transactions.
• Here are some tasks that come under TCL:

• Commit: It is used to save the transaction on the database.
• Rollback: It is used to restore the database to the original since the last Commit.
• Savepoint:- Used to save parts of tasks.

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