Thread: jdbc program

/*program for implementing Desc command of oracle database in java*/

import java.sql.*;
public class jdbc2 {
	public static void main(String arg[])throws ClassNotFoundException,SQLException
	{
		Class.forName("oracle.jdbc.driver.OracleDriver");
		Connection con=DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:orcl","scott","tiger");
		if(con==null)
		{	System.out.println("sory unable to connect to DataBase " +
					"Try again after sometime");
                                        return;
                }
		else
			System.out.println("connected successfully");
 
		String table=arg[0];
		Statement stmt=con.createStatement();
		ResultSet rs=stmt.executeQuery("select * from "+ table);
		ResultSetMetaData rsmd=rs.getMetaData();
		int n=rsmd.getColumnCount();
		String s;
		System.out.println("Name"+"\t\t\t"+"  Null?"+"\t\t\t"+"Type");
		System.out.println("--------------------    -----------------    --------------");
		for(int i=1;i<=n;i++)
		{
 
			if(rsmd.isNullable(i)==ResultSetMetaData.columnNoNulls)
				s="  NOT NULL";
			else
		        s="          ";
			if(rsmd.getColumnTypeName(i)=="DATE")
				System.out.println(rsmd.getColumnName(i)+"\t"+"\t"+"\t"+"\t"+"\t"+rsmd.getColumnTypeName(i));
			else
			{
				if(rsmd.getScale(i)==0)
			System.out.println(rsmd.getColumnName(i)+"\t"+"\t"+"\t"+
			       s+"\t"+"\t"+rsmd.getColumnTypeName(i)+
                			"("+rsmd.getPrecision(i)
			                   +")");
				else
					System.out.println(rsmd.getColumnName(i)+"\t"+"\t"+"\t"+
						       s+"\t"+"\t"+rsmd.getColumnTypeName(i)+
			                			"("+rsmd.getPrecision(i)+","
						                   +rsmd.getScale(i)+")");
		}}
		rs.close();
		rs=null;
		stmt.close();
		stmt=null;
		con.close();
		con=null;

}
}


compiling and executing of this program
--------------------------------------------
1. compile as usual
2 execute this program by providing table name as command line argument

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