A simple comparison of DDL and DML in DBMS

Data definition language (DDL) and data manipulation language (DML) together form the database language. So what's the difference between them? The following article will introduce you to DDL and DML in DBMS, briefly compare them, and let you understand the difference between DDL and DML. I hope it will be helpful to you.

What is DDL?

DDL stands for Data Definition Language, which defines the database structure or database schema. Other attributes of the data defined in the database can be defined as attribute domains; it also provides the ability to specify some constraints to maintain Data consistency tools. [Video tutorial recommendation: MySQL tutorial]

DDL commands help create the structure of databases and other database objects. Its commands are automatically committed; therefore, changes are permanently saved in the database.

Some DDL commands include create, drop, alter, truncate and rename. The create command helps to create new databases and tables; the drop command helps to delete databases and tables; the alter command helps to modify existing database objects; the truncate command is used to delete all contents in the table; the rename command is used to re- Name the contents of the database. These are some common DDL commands.

What is DML?

DML stands for Data Manipulation Language and the schema (table) it creates is populated using Data Manipulation Language. DDL populates rows of a table, each row is called a Tuple. Using DML, you can insert, modify, delete and retrieve information from tables.

DML commands help manage the data stored in the database. However, DML commands are not submitted automatically. Therefore, the changes are not permanent. Therefore, the operation can be rolled back.

Some DML commands include insert, update, delete and select. The insert command helps to store new records or rows into the table; the update command helps to modify existing records in the table; the delete command allows to delete a record or a group of records from the table; the select command allows to delete one or more records from the table. Retrieve specific records from a table.

The difference between DDL and DML in DBMS

##1. Essential difference

DDL stands for Data Definition Language and is a SQL command that helps create a database schema. However, DML stands for Data Manipulation Language, a type of SQL commands that helps in retrieving and managing data in relational databases.

2. Differences in commands

Commonly used commands in DDL are: create, drop, alter, truncate, rename, etc. However, commonly used commands in DML are: insert, update, delete, select, etc.

3. Difference in impact

DDL commands will affect the entire database or table, but DML commands will affect one or more records in the table.

4. Differences in rollback

SQL statements with DDL commands cannot be rolled back; SQL statements with DML commands can be rolled back.

Conclusion:

In order to form a database language, both DDL and DML are necessary. The main difference between DDL and DML is: DDL helps in changing the structure of the database while DML helps in managing the data in the database.

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