dboperation.java

JAVA编写的远程教育程序,包含了教育学的基本思想和网络应用程序的基本开发模式

package com.whatratimes.dbms;

import org.apache.struts.validator.DynaValidatorActionForm;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;
import com.whatratimes.dbms.*;

import java.util.Hashtable;
import java.util.Enumeration;

/**
 * User: Tao
 * Date: May 15, 2003
 * Time: 8:42:44 PM
 */
public class DBOperation
{


    public static int CMD(ActionForm actionForm, ActionMapping actionMapping, String primary_key)
    {
        String table_name = actionMapping.getAttribute();

        return CMD(actionForm, actionMapping, primary_key, table_name);
    }

    public static int CMD(ActionForm actionForm, ActionMapping actionMapping, String primary_key, String table_name)
    {

        DynaValidatorActionForm form = (DynaValidatorActionForm) actionForm;

        String operation = form.get("Operation").toString();


        Hashtable prop = new Hashtable(form.getMap());

        int rows = 0;


        if ("Create".equals(operation))
        {
            InsertSQLExecuter sql = new InsertSQLExecuter();

            sql.appendTableName(table_name);

            sql.appendValuesByHashtable(prop);

            rows = sql.executeUpdate();

        } else if ("Modify".equals(operation))
        {

            UpdateSQLExecuter sql = new UpdateSQLExecuter();

            sql.appendWhereCondition(primary_key, "=", form.get(primary_key));
            sql.appendTableName(table_name);

            sql.appendValuesByHashtable(prop);

            rows = sql.executeUpdate();

        } else if ("Delete".equals(operation))
        {
            DeleteSQLExecuter sql = new DeleteSQLExecuter();

            sql.appendTableName(table_name);
            sql.appendWhereCondition(primary_key, "=", form.get(primary_key));
            rows = sql.executeUpdate();
        }

        return rows;

    }

    public static int CMD( Hashtable prop, String table_name, Hashtable primary_keys )
    {

        int rows = 0;


        String operation = prop.get("Operation").toString();

        if ("Create".equals(operation))
        {
            InsertSQLExecuter sql = new InsertSQLExecuter();

            sql.appendTableName(table_name);

            sql.appendValuesByHashtable(prop);

            rows = sql.executeUpdate();

        } else if ("Modify".equals(operation))
        {

            UpdateSQLExecuter sql = new UpdateSQLExecuter();

            sql.appendTableName(table_name);

            sql.appendValuesByHashtable(prop);

            Enumeration enu = primary_keys.keys();
            while ( enu.hasMoreElements())
            {
                Object key = enu.nextElement();
                sql.appendWhereCondition(key.toString(), "=", primary_keys.get(key));
            }

            rows = sql.executeUpdate();

        } else if ("Delete".equals(operation))
        {
            DeleteSQLExecuter sql = new DeleteSQLExecuter();

            sql.appendTableName(table_name);
            Enumeration enu = primary_keys.keys();
            while ( enu.hasMoreElements())
            {
                Object key = enu.nextElement();
                sql.appendWhereCondition(key.toString(), "=", primary_keys.get(key));
            }
            rows = sql.executeUpdate();
        }

        return rows;

    }

}