DATABASE LANGUAGES -Database system provide a Data Definition language to specify the database schema and Data Manipulation Language to express the database query and updates.The data Definition and the data manipulation language are not two separated language ,Instead they simply form parts of a database languages such as widely used in SQL language .
Data Manipulation Language -Data Manipulation language are language that enables user to access the data and manipulate the data as organized by appropriate model.the type of access are -;
1 Retrieval of information stored in the database .
2 Insertion the new information into the database .
3 Deletion of information from the database .
4 Manipulation of information stored in the database.
There are two types of Data Manipulation language -;
1 Procedural DML -; require a user to specify what data are needed .how to get those data .
2 Declarative DML -: require a user to specify what data are needed without specifying hoe to get those data .
Data Definition Language-; We specify database schema by the set of definition expressed by a special language called Data Definition Language .The DDL is used to specify additional property of the data .
We also specify the storage structure and access method by database system by a set of statement in special type of DDL called a Data storage and Data definition Language . These statement define the implementation detail of the database schema ,which are usually hidden from the users.
The data value stored in the database must be satisfy certain consistency constraints
Data Manipulation Language -Data Manipulation language are language that enables user to access the data and manipulate the data as organized by appropriate model.the type of access are -;
1 Retrieval of information stored in the database .
2 Insertion the new information into the database .
3 Deletion of information from the database .
4 Manipulation of information stored in the database.
There are two types of Data Manipulation language -;
1 Procedural DML -; require a user to specify what data are needed .how to get those data .
2 Declarative DML -: require a user to specify what data are needed without specifying hoe to get those data .
Data Definition Language-; We specify database schema by the set of definition expressed by a special language called Data Definition Language .The DDL is used to specify additional property of the data .
We also specify the storage structure and access method by database system by a set of statement in special type of DDL called a Data storage and Data definition Language . These statement define the implementation detail of the database schema ,which are usually hidden from the users.
The data value stored in the database must be satisfy certain consistency constraints
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