DatabaseMetaData interface

DatabaseMetaData interface:

DatabaseMetaData interface provides methods to get meta data of a database such as database product name, database product version, driver name, name of total number of tables, name of total number of views etc.

Commonly used methods of DatabaseMetaData interface

·         public String getDriverName()throws SQLException: it returns the name of the JDBC driver. ·         public String getDriverVersion()throws SQLException: it returns the version number of the JDBC driver. ·         public String getUserName()throws SQLException: it returns the username of the database. ·         public String getDatabaseProductName()throws SQLException: it returns the product name of the database. ·         public String getDatabaseProductVersion()throws SQLException: it returns the product version of the database. ·         public ResultSet getTables(String catalog, String schemaPattern, String tableNamePattern, String[] types)throws SQLException: it returns the description of the tables of the specified catalog. The table type can be TABLE, VIEW, ALIAS, SYSTEM TABLE, SYNONYM etc.

How to get the object of DatabaseMetaData:

The getMetaData() method of Connection interface returns the object of DatabaseMetaData. Syntax:

1.    public DatabaseMetaData getMetaData()throws SQLException  

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Simple Example of DatabaseMetaData interface :

1.    import java.sql.*;  

2.    class Dbmd{  

3.    public static void main(String args[]){  

4.    try{  

5.    Class.forName("oracle.jdbc.driver.OracleDriver");  

6.      

7.    Connection con=DriverManager.getConnection(  

8.    "jdbc:oracle:thin:@localhost:1521:xe","system","oracle");  

9.      

10. DatabaseMetaData dbmd=con.getMetaData();  

11.   

12. System.out.println("Driver Name: "+dbmd.getDriverName());  

13. System.out.println("Driver Version: "+dbmd.getDriverVersion());  

14. System.out.println("UserName: "+dbmd.getUserName());  

15. System.out.println("Database Product Name: "+dbmd.getDatabaseProductName());  

16. System.out.println("Database Product Version: "+dbmd.getDatabaseProductVersion());  

17.   

18. con.close();  

19.   

20. }catch(Exception e){ System.out.println(e);}  

21.   

22. }  

23. }  

Output:Driver Name: Oracle JDBC Driver

       Driver Version: 10.2.0.1.0XE

       Database Product Name: Oracle

       Database Product Version: Oracle Database 10g Express Edition

                                 Release 10.2.0.1.0 -Production

Example of DatabaseMetaData interface that prints total number of tables :

1.    import java.sql.*;  

2.    class Dbmd2{  

3.    public static void main(String args[]){  

4.    try{  

5.    Class.forName("oracle.jdbc.driver.OracleDriver");  

6.      

7.    Connection con=DriverManager.getConnection(  

8.    "jdbc:oracle:thin:@localhost:1521:xe","system","oracle");  

9.      

10. DatabaseMetaData dbmd=con.getMetaData();  

11. String table[]={"TABLE"};  

12. ResultSet rs=dbmd.getTables(null,null,null,table);  

13.   

14. while(rs.next()){  

15. System.out.println(rs.getString(3));  

16. }  

17.   

18. con.close();  

19.   

20. }catch(Exception e){ System.out.println(e);}  

21.   

22. }  

23. }  

Example of DatabaseMetaData interface that prints total number of views :

1.    import java.sql.*;  

2.    class Dbmd3{  

3.    public static void main(String args[]){  

4.    try{  

5.    Class.forName("oracle.jdbc.driver.OracleDriver");  

6.      

7.    Connection con=DriverManager.getConnection(  

8.    "jdbc:oracle:thin:@localhost:1521:xe","system","oracle");  

9.      

10. DatabaseMetaData dbmd=con.getMetaData();  

11. String table[]={"VIEW"};  

12. ResultSet rs=dbmd.getTables(null,null,null,table);  

13.   

14. while(rs.next()){  

15. System.out.println(rs.getString(3));  

16. }  

17.   

18. con.close();  

19.   

20. }catch(Exception e){ System.out.println(e);}  

21.   

22. }  

23. }