What is a DDL, DML and DCL concept in RDBMS world?
DDL (Data definition language) defines your database structure. CREATE and ALTER
are DDL statements as they affect the way your database structure is organized.
DML (Data Manipulation Language) lets you do basic functionalities like INSERT,
UPDATE, DELETE and MODIFY data in database.
DCL (Data Control Language) controls you DML and DDL statements so that your data
is protected and has consistency. COMITT and ROLLBACK are DCL control statements.
DCL guarantees ACID fundamentals of a transaction.
DDL : Data definition language -> to define the database objects structure
DML : Data Manipulation language -> to Manipulate with the datas stored in the structure.
DCL : To make control over the datas and transaction in the T-SQL Statements.
Venkatesan Prabu. J
A Data Definition Language (DDL) is a computer language for defining data structures. The term was first introduced in relation to the Codasyl database model, where the schema of the database was written in a Data Definition Language describing the records, fields, and "sets" making up the user Data Model. Initially it referred to a subset of SQL, but is now used in a generic sense to refer to any formal language for describing data or information structures, like XML schemas.
Data Manipulation Language (DML) is a family of computer languages used by computer programs or database users to retrieve, insert, delete and update data in a database.
Currently, the most popular data manipulation language is that of SQL, which is used to retrieve and manipulate data in a Relational database. Other forms of DML are those used by IMS/DLI, CODASYL databases (such as IDMS), and others.
Data manipulation languages were initially only used by computer programs, but (with the advent of SQL) have come to be used by people, as well.
Data Manipulation Languages have their functional capability organized by the initial word in a statement, which is almost always a verb. In the case of SQL, these verbs are:
This makes the nature of the language into a set of imperative statements (commands) to the database.
Data Manipulation Languages tend to have many different flavors and capabilities between database vendors. There has been a standard established for SQL by ANSI, but vendors still provide their own extensions to the standard while not implementing the entire standard.
There are two types of Data Manipulation languages: