Detailed explanation of JDBC Programming Model.

Advanced Java: 03

Q.1 Explain about JDBC Programming Model?

a. Requesting for connection or log in to the database server:

• Java program and database server are communicating with each other is like client server architecture.
• It's a client duty request for connection.
• Java program being a client should get connected to the database server.
• In two ways java program gets connected to database server.

1. Driver Manager: (without connection pooling)
2. Datasource: (With Connection pooling)

Q.2 How java program gets connection to the database server?

• Java program makes use of Driver-Manager or DataSource.
• By calling getConnection( ) method on Driver Manager or DataSource, JDBC client request for database connection. 
• Connection connection = DriverManager.getConnection( )
• getConnection( ) is a library method.
• It is a static Method.
• It is used for database connection.
• java program logged into the database server that logging is called one session.
• Object oriented representation of JDBC client session with the database server is nothing but connection object.
• connection is an object. it represents java program session.
• As long as this session is active (i: e Connection is open) so long java program can perform CRUD operation with the database.

Q.3 How to create Statement Object?

• By calling createStatement() method on the connection object, statement object is created.
• Statement statement = connection.createStatement( )
• createStatement( ) method is a instance method.
• It is not a static method; it is on the object method.

Q.4 Why to Create Statement Object?

• Statement object is the designatory object to submit an SQL Statement from a java program to the DBMS.
• when we want to send a SQL, statement use statement object.

Q.5 How to submit the SQL Statement?

• java program objective is performing CRUD operation.
• Without statement we cannot perform CRUD Operation.
• Statement methods have two methods to submit an SQL Statement to the DBMS.

1. executeUpdate( String DML)
2. executeQuery( String DRL)

• executeUpdate() method is used to submit INSERT, UPDATE & DELETE Statement to the DBMS.
• executeQuery() method is used to submit SELECT Statement to the DBMS.

Q.6 Why and How to close the statement?

• by calling close () method on the statement object, statement is closed.
• statement.close()
• To release JDBC resources of the JDBC client maintained by the database server, statement should be in closed in JDBC Client.

Q. 7 Why and How to Close the Statement?

• By calling Close () method on the connection object, connection is closed in the JDBC Client.
• To release networking resources of the JDBC client maintained by the database server, connection should be closed in JDBC client.
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Q.8 What is Database?

• Database is not MySQL, MongoDB, oracle 
• Database is a collection of tables of the project.
• Database = Tables of the project + associated data.
• database is maintained by database server/DBMS/ RDBMS.
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Q.9 How Many Types of DBMS?

• DBMS are of so many types.

1. Network based Database Management System.
2. Object Oriented based DBMS
3. RDBMS almost used in industry.