Example: ResultSetMetaData interface for IBM^® Developer Kit for Java™

Note: Read the Code example disclaimer for important legal information.

import java.sql.*;

/**
ResultSetMetaDataExample.java

This program demonstrates using a ResultSetMetaData and 
a ResultSet to display all the metadata about a ResultSet
created querying a table.  The user passes the value for the 
table and library in.
**/
public class ResultSetMetaDataExample {

    public static void main(java.lang.String[] args) 
    {
        if (args.length != 2) {
            System.out.println("Usage:  java ResultSetMetaDataExample <library> <table>");
            System.out.println("where <library> is the library that contains <table>");
            System.exit(0);
        }

        Connection con = null; 
        Statement s = null;
        ResultSet rs = null;
        ResultSetMetaData rsmd = null;

        try {
            // Get a database connection and prepare a statement.
            Class.forName("com.ibm.db2.jdbc.app.DB2Driver");
            con = DriverManager.getConnection("jdbc:db2:*local");

            s = con.createStatement();

            rs = s.executeQuery("SELECT * FROM " + args[0] + "." + args[1]);
            rsmd = rs.getMetaData();

            int colCount = rsmd.getColumnCount();
            int rowCount = 0;
        for (int i = 1; i <= colCount; i++) {
                System.out.println("Information about column " + i);
                System.out.println("   Name..........: " + rsmd.getColumnName(i));
                System.out.println("   Data Type.....: " + rsmd.getColumnType(i) + 
                                   " ( " + rsmd.getColumnTypeName(i) + " )");
                System.out.println("   Precision.....: " + rsmd.getPrecision(i));
                System.out.println("   Scale.........: " + rsmd.getScale(i));
                System.out.print  ("   Allows Nulls..: ");
                if (rsmd.isNullable(i)==0) 
                    System.out.println("false");
                else
                    System.out.println("true");
            }

        } catch (Exception e) {
            // Handle any errors.
            System.out.println("Oops... we have an error... ");
            e.printStackTrace();
        } finally {
            // Ensure we always clean up.  If the connection gets closed, the
            // statement under it closes as well. 
            if (con != null) {
                try {
                    con.close();
                } catch (SQLException e) {
                    System.out.println("Critical error - cannot close connection object");
                }
            }
        }
    }
}