Java - describing DB table (DESC table)

JDBC allows us to get metadata information of the DB and DB tables. Our aim here is to describe a table, we need to get the metadata of the DB table. We can achieve this with ResultSetMetaData interface.

All you need to do is -

1. just create a statement with plain select query i.e.;

SELECT * FROM EMPLOYEE

2. Get the ResultSetMetaData object reference using resultSet.getMetaData();

3. Access column name and data type

import java.sql.*;

/**
 * A demo class to explain DESC DB table
 * @author Santhosh Reddy Mandadi
 * @since 17-Aug-2012
 * @version 1.0
 */

public class DescDemo
{
  public static void main(String args[]) throws Exception
  {
    String driverClass;
    String jdbcURL;
    String userName;
    String password;
    String tableName;    
    driverClass = "oracle.jdbc.driver.OracleDriver";
    jdbcURL = "jdbc:oracle:@localhost:1521:xe";
    userName = "scott";
    password = "tiger";
    tableName = "EMPLOYEE";
    Class.forName(driverClass);
    Connection connection = DriverManager.getConnection(jdbcURL, userName, password);
    Statement statement = connection.createStatement();
    ResultSet resultSet = statement.executeQuery("SELECT * FROM "+tableName);
    ResultSetMetaData metaData = resultSet.getMetaData();
    System.out.println("Number of columns: "+metaData.getColumnCount());
    System.out.println("Table description...!");
    for(int i=1;i< metaData.getColumnCount();i++)
    {
      System.out.println(metaData.getColumnName(i)+"\t"+metaData.getColumnTypeName(i));
    }
  }
}