Difference between DDL and VDL

Question

What is View Definition Language ?

What is the difference between Data Definition Language and View Definition Language ?

Solution 1

View Definition Language is a language for specifying user interfaces. From what I understand it's the statements in SQL or other DB's that retrieve the data and shows it to the user.

You can read more in this link https://www.it.uu.se/research/project/ikaros/vdl.pdf

Data Definition Language or data description language (DDL) is a syntax similar to a computer programming language for defining data structures, especially database schemas. In other words it's the statements which purpose is to define how the data is stored (without showing it), like CREATE, ALTER, DROP, TRUNCATE, etc..

You can read more here: http://en.wikipedia.org/wiki/Data_definition_language

Solution 2

DBMS Support a variety of users and provides appropriate languages and interface or each category of users.

Data Definition Language (DDL): This Language is used define data structures and specially database schemas. these statements are used to create, alter, or drop data structures. ALTER ,CREATE ,DROP are some examples of DDL.

View Definition Language (VDL): This language is used to specify user views and their mapping to conceptual schema. It defines the subset of records available to classes of users. It creates virtual tables and the view appears to users like conceptual level.It specifies user interfaces.