Data Definition Language

data definition lanaguage ddl overcoded

A data definition language (DDL) is a syntax provided by a database management system (DBMS) used to define the structure of data (schema) within a database. This type of language is used to create and modify object representations such as tables, indexes, and views.

In structured query language (SQL) DDL commands are used to access, manipulate, and update data. Examples of these commands include CREATE, DROP, and DELETE. As the syntax implies, the CREATE command can be used to perform actions such as CREATE TABLE or CREATE VIEW based on programmer intent.

Sequences of DDL commands are often preserved in scripts for common or repeated operations. For example, the Django framework provides a built-in database migration management system that auto-generates DDL to create or alter database schema based on its class-based modeling system.

Data definition languages are very similar to Data manipulation language (DML). In practice, these are the same root language and merely subsets of commands. For example, data definitions are made with the CREATE, DELETE, and DROP commands whereas data manipulation language consists of UPDATE, SELECT, and INSERT.

Zαck West
BSc Computer Science, BSc Technology Education. Life-long learner and entrepreneur specializing in design, digital marketing, and web app development. Fascinated by natural systems, concurrency, and the nature of consciousness.