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Showing posts from December 9, 2020

What is Data definition language?

  Data definition Language :-   it is a standard for commands that define the different structures in a database. §   It creates , modify , and remove database objects such as tables , indexes , and users. §   CREATE , ALTER , DROP   are some common data definition language. §   It is used in database applications that are considered a subset of SQL( Structured Query Language) §   However , a DDL(Data Definition Language) may also define other types of data , such as XML. §   It has pre-defined syntax for describing data. For example   to build a new table by using   SQL syntax then   the   CREATE command is used , followed by parameters for the table name and column definitions. §   It can also define the name of each column and the associated data type. Once a table is created the it can be modified by using ALTER command and to delete the table we can be use DROP   command. §   Since , DDL is a s...