DataBaseMetaData

  • JDBC DatabaseMetaData is an interface of java.sql.*; package.
  • DatabaseMetaData is generally implemented by the Database application vendors to know the capability of Database Management System in combination with the driver based JDBC technology.
  • This interface is the tool for the user who need to discover how to deal with underlying database.
  • Some meta data methods returns the string in form of ResultSet object.
  • Then we retrieve data from this object with getInt(), and getString() methods.
  • Some metadata objects takes argument also.
  • DatabaseMetaData provides comprehensive information about the database.
  • This interface is implemented by the driver vendors to allow the user to obtain information about the tables of a relational database as a part of JDBC application.
  • User can use this interface to deal with various underlying DBMSs.
  • Some of the methods are:-
    getDatabaseMajorVersion() getDatabaseMinorVersion()
    getDatabaseProductName() getDatabaseProductVersion()
    getMaxRowSize() getPrimaryKeys()
    getURL() getUserName() etc.

JDBC provides four interfaces that deal with database metadata
  1. java.sql.DatabaseMetaData: about the database as a whole: table names, table indexes, database product name and version, and actions the database supports.
  2. java.sql.ResultSetMetaData: about the types and properties of the columns in a ResultSet object.
  3. java.sql.ParameterMetaData: about the types and properties of the parameters in a PreparedStatement object.
  4. javax.sql.RowSetMetaData: about the columns in a RowSet object.

RowSet

  • JDBC RowSet is an interface ofjavax.sql.rowset interface.
  • This interface is wrapper around a ResultSet object that makes possible to use resultSet as java beans object.
  • It can be one bean that makes available for composing of an application. Because a it continually maintain a connection JDBC connection to the database.
  • Another advantage of JDBC RowSet is that it is used to makes ResultSet object scrollable and updateable.
  • By default all the RowSet object are scrollable and updateable.
  • An Example of Row Set Event listener is given below, To run this example at first create a database name student and create a table also named student
    • CREATE TABLE student ( 
RollNo int(9)  PRIMARY KEY NOT NULL, 
Name tinytext NOT NULL, 
Course varchar(25) NOT NULL, 
Address text 
 );
  • Then insert the value into it as
    • insert into student VALUES(1, 'Amit', 'BCA', 'Chennai') ;
insert into student VALUES(2, 'Sumit', 'MCA', 'Mumbai') ;