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This article mainly introduces what are the differences between DDL and DML in DBMS. What is introduced in this article is very detailed and has a certain reference value. Interested friends must read it!

What is DDL?

DDL stands for data definition language, which defines the database structure or database schema, can define other properties of the data defined in the database as attribute fields, and provides tools to specify some constraints to maintain data consistency.

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

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

What is DML?

DML stands for data manipulation language, and the schemas (tables) it creates are populated with data manipulation languages. DDL populates the rows of the table, and each row is called Tuple. Using DML, you can insert, modify, delete, and retrieve information in tables.

The DML command helps manage the data stored in the database. However, the DML command is not automatically submitted. Therefore, the change is not permanent. Therefore, the operation can be rolled back.

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

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 database schemas. DML, on the other hand, stands for data manipulation language and is a SQL command that helps to retrieve and manage data in relational databases.

2. The difference in command

The commands commonly used in DDL are: create,drop,alter,truncate, rename, and so on. However, the commands commonly used in DML are: insert,update,delete, select, and so on.

3. The difference in influence

The DDL command affects the entire database or table, but the DML command affects 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:

Both DDL and DML are required to form a database language. The main difference between DDL and DML is that DDL helps change the structure of the database, while DML helps manage the data in the database.

These are all the contents of this article entitled "what are the differences between DDL and DML in DBMS". Thank you for reading! Hope to share the content to help you, more related knowledge, welcome to follow the industry information channel!

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