JAVA Database Maintenance Code


1.
import java.io.*;
import java.sql.*;
public class dbpg1 {

    static void marker(){
        for (int i=1;i<=50;i++)
        {
            System.out.print("*");
        }
        System.out.println();
    }
    public static void main(String[] args) {
        Connection con;
        Statement st;
        BufferedReader bin;
        ResultSet rs;
        ResultSetMetaData rm;
        String euname, epwd, eno,salary;
        int ch, nocol,eid;

        try
        {
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
            con = DriverManager.getConnection("jdbc:odbc:chanstaff");
            st = con.createStatement();
            bin = new BufferedReader(new InputStreamReader(System.in));
            while(true){
                System.out.println("Choose Option");
                System.out.println("1. Select");
                System.out.println("2. Insert");
                System.out.println("3. Update");
                System.out.println("4. Delete");
                System.out.println("0. Exit");
                ch = Integer.parseInt(bin.readLine());
           if (ch==1)

           {
               rs = st.executeQuery("select * from stafftab");
               rm = rs.getMetaData();
               nocol= rm.getColumnCount();
               marker();
               for(int i=1; i<=nocol; i++)
               {
                   System.out.print(rm.getColumnName(i)+"\t\t");
               }
               System.out.println();
               marker();
               while(rs.next())
               {
               for(int i=1; i<=nocol; i++)
               {
                   System.out.print(rs.getString(i) +"\t\t");
               }
               System.out.println();
               }
                marker();

           }
           else if(ch==2)
                   {
            do
            {
                System.out.println("Enter user name");
                euname = bin.readLine();
                System.out.println("Enter pasword");
                epwd = bin.readLine();
                //System.out.println("Enter Salary");
                //salary = bin.readLine();
               st.execute("insert into stafftab (uname,pwd)values('"+euname+"','"+epwd+"')");
//st.execute("insert into stafftab (uname,pwd)values('"+euname+"','"+epwd+"')");
                System.out.println("1 Record inserted");
                System.out.println("Continue ? [y/n]");
                eno = bin.readLine();
            }while(eno.equalsIgnoreCase("y"));
         }
           else if(ch==3)
           {
    System.out.println("Enter id for the record to do edit");
               eid  = Integer.parseInt(bin.readLine());
               System.out.println("Enter uname to change :");
               euname = bin.readLine();
               System.out.println("Enter new password");
               epwd = bin.readLine();
              
             //  st.execute("update stafftab set uname='"+euname+"',pwd='"+epwd+"'where ID="+eid);
st.execute("update stafftab set uname='"+euname+"',pwd='"+epwd+"'where ID="+eid+"");
               System.out.println("1 Record Updated");
con.setAutoCommit(true);

           }
           else if(ch==4)
           {
               System.out.println("Enter uname. to Delete :");
               euname = bin.readLine();
               //st.execute("delete from stafftab where uname='bala'");
 st.execute("delete from stafftab where uname='"+euname+"'");
con.setAutoCommit(true);
               System.out.println("Record Deleted");
           }
           else if(ch==0)
           {
            bin.close();
            con.close();
            System.exit(0);
           }
        }
        }
        catch(Exception e)
        {
            System.out.println("Error :"+e.getMessage());
        }
    }
}
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