The metadata means data about data i.e. we can get further information from the data.
If you have to get metadata of a table like total number of column, column name, column type etc. , ResultSetMetaData interface is useful because it provides methods to get metadata from the ResultSet object.
Method | Description |
---|---|
public int getColumnCount()throws SQLException | it returns the total number of columns in the ResultSet object. |
public String getColumnName(int index)throws SQLException | it returns the column name of the specified column index. |
public String getColumnTypeName(int index)throws SQLException | it returns the column type name for the specified index. |
public String getTableName(int index)throws SQLException | it returns the table name for the specified column index. |
The getMetaData() method of ResultSet interface returns the object of ResultSetMetaData. Syntax: |
public ResultSetMetaData getMetaData()throws SQLException
import java.sql.*; class Rsmd{ public static void main(String args[]){ try{ Class.forName("oracle.jdbc.driver.OracleDriver"); Connection con=DriverManager.getConnection( "jdbc:oracle:thin:@localhost:1521:xe","system","oracle"); PreparedStatement ps=con.prepareStatement("select * from emp"); ResultSet rs=ps.executeQuery(); ResultSetMetaData rsmd=rs.getMetaData(); System.out.println("Total columns: "+rsmd.getColumnCount()); System.out.println("Column Name of 1st column: "+rsmd.getColumnName(1)); System.out.println("Column Type Name of 1st column: "+rsmd.getColumnTypeName(1)); con.close(); }catch(Exception e){ System.out.println(e);} } }