module.cs

实现c#的计费系统 包括计费员 管理员 普通用户等几种操作角色 课程设计时编写

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;

namespace myBusinessRole
{
    /// <summary>
    /// 模块表
    /// </summary>
    class Module
    {
        #region 字段定义
        string moduleID;//模块id
        string moduleName;//模块名称
        string remark;//备注
        #endregion

        #region 属性添加
        public string ModuleID
        {
            get { return moduleID; }
            set { moduleID = value; }
        }
        public string ModuleName
        {
            get { return moduleName; }
            set { moduleName = value; }
        }
        public string Remark
        {
            get { return remark; }
            set { remark = value; }
        }
        #endregion

        #region IDbOperate成员

        #region 清空所有变量 void Clear()
        /// <summary>
        ///Clear()
        ///</summary>
        public void Clear()
        {
             moduleID="";//模块id
             moduleName="";//模块名称
             remark="";//备注

        }
        #endregion

        #region 判断能否删除 public bool IsDeleteFromKey()
        /// <summary>
        ///IsDeleteFromKey() 根据主键判断能否删除此记录
        ///</summary>
        public bool IsDeleteFromKey()
        {

            //定义变量
            bool dbOk = false;
            bool isDelete = false;
            try
            {
                //ModuleRole 有外键关系，要判断ModuleRole表中是否有记录存在
                ModuleRole moduleRole = new ModuleRole();
                moduleRole.ModuleID = moduleID;
                dbOk = moduleRole.IsExist(" ModuleID = '" + moduleID + "'");
                if (dbOk)
                {
                    //记录存在，不能删除
                    isDelete = false;
                }
                else
                {
                    //没有有关的记录，可以删除
                    isDelete = true;
                }
            }
            catch (Exception e)
            {
                throw e;
            }
            return isDelete;
        }
        #endregion

        #region 根据主键删除 public bool DeleteFromKey()
        /// <summary>
        ///DeleteFromKey() 
        ///在IsDeleteFromKey()之后应用的方法
        ///如果能删除，根据主键删除
        ///</summary>
        public bool DeleteFromKey()
        {

            //生成Sql语句
            StringBuilder Sql = new StringBuilder();
            Sql.Append(" DELETE FROM Module ");
            Sql.Append(" WHERE moduleID='" + moduleID + "'");
            try
            {
                //访问数据库并返回
                DB db = new DB();
                return db.ExecuteSql(Sql.ToString());
            }
            catch (Exception e)
            {
                throw e;
            }
        }
        #endregion

        #region 根据条件删除 public bool Delete(string condition)
        /// <summary>
        ///Delete()  根据条件删除， condition为不含“where”的条件
        ///建议慎重使用，因为没有对应的判断，删除不能保证成功
        ///如果出错，返回的是数据库不能删除的错误信息
        ///</summary>
        public bool Delete(string condition)
        {

            //生成Sql语句
            StringBuilder Sql = new StringBuilder();
            Sql.Append(" DELETE FROM Module ");
            if (!(condition == null || condition == ""))
            {
                Sql.Append(" WHERE " + condition);
            }
            try
            {
                //访问数据库并返回
                DB db = new DB();
                return db.ExecuteSql(Sql.ToString());
            }
            catch (Exception e)
            {
                throw e;
            }
        }
        #endregion

        #region 根据主键更新 public bool UpdateFromKey()
        /// <summary>
        ///UpdateFromKey() 根据主键更新，由前台页面保证数据的合法性
        ///更新的内容在属性中存放。
        ///</summary>
        public bool UpdateFromKey()
        {

            //生成Sql语句
            StringBuilder Sql = new StringBuilder();
            Sql.Append(" UPDATE Module SET ");
            Sql.Append(" ModuleID='" + moduleID + "' ");
            Sql.Append(" ,ModuleName='" + moduleName + "' ");
            Sql.Append(", Remark='" + remark + "'");
            Sql.Append(" WHERE ModuleID='" + moduleID + "'");
            try
            {
                //访问数据库并返回
                DB db = new DB();
                return db.ExecuteSql(Sql.ToString());
            }
            catch (Exception e)
            {
                throw e;
            }
        }
        #endregion

        #region 添加一条记录 public bool Insert()
        /// <summary>
        ///Insert() 添加一条记录，添加的内容在属性中存放
        ///由前台页面保证数据的合法性
        ///</summary>
        public bool Insert()
        {

            //生成Sql语句
            StringBuilder Sql = new StringBuilder();
            Sql.Append(" INSERT INTO Module(");
            Sql.Append(" ModuleID,ModuleName, Remark)");
            Sql.Append(" VALUES (");
            Sql.Append(" '" + moduleID + "' ");
            Sql.Append(" ,'" + moduleName + "' ");
            Sql.Append(" ,'" + remark + "' ");
            Sql.Append(" )");
            try
            {
                //访问数据库并返回
                DB db = new DB();
                return db.ExecuteSql(Sql.ToString());
            }
            catch (Exception e)
            {
                throw e;
            }
        }
        #endregion

        #region 给定条件的记录是否存在 public bool IsExist(string condition)
        /// <summary>
        ///IsExist() 给定条件的记录是否存在
        ///</summary>
        public bool IsExist(string condition)
        {

            //生成Sql语句
            StringBuilder Sql = new StringBuilder();
            Sql.Append(GetSqlString(condition));

            //定义返回变量
            bool dbOk = false;
            string retOneData;//一条纪录
            try
            {
                //访问数据库
                DB db = new DB();
                retOneData = db.GetOneData(Sql.ToString());



                //判断
                if (retOneData != null && retOneData != "")
                {
                    dbOk = true;
                }
            }
            catch (Exception e)
            {
                throw e;
            }
            return dbOk;
        }
        #endregion

        #region 根据条件查询  public DataTable Query(string condition)
        /// <summary>
        ///Query() 根据条件查询，condition为不含“where”的条件
        ///由查询者保证condition的合法性
        ///</summary>
        public DataTable Query(string condition)
        {
            try
            {
                //访问数据库并返回
                DB db = new DB();
                return db.GetDataTable(GetSqlString(condition));
            }
            catch (Exception e)
            {
                throw e;
            }
        }
        #endregion

        #region 无条件查询  public DataTable Query()
        /// <summary>
        ///Query() 无条件查询
        ///</summary>
        public DataTable Query()
        {
            try
            {
                //访问数据库并返回
                DB db = new DB();
                return db.GetDataTable(GetSqlString(""));
            }
            catch (Exception e)
            {
                throw e;
            }
        }
        #endregion

        #region 根据主键查询 public Ret QueryFromKey()
        /// <summary>
        ///QueryFromKey() 根据主键查询
        ///要查询的主键在属性中存放，查询的结果存放在属性中
        ///</summary>
        public DataTable QueryFromKey()
        {

            //生成Sql语句
            StringBuilder Sql = new StringBuilder();
            Sql.Append(GetSqlString("ModuleID ='" + moduleID + "' "));

            //清空属性值
            this.Clear();

            //定义返回变量
            DataTable dt = new DataTable();

            try
            {
                //访问数据库
                DB db = new DB();
                dt = db.GetDataTable(Sql.ToString());

                //若访问数据库成功就给属性赋值
                if (dt.Rows.Count > 0)
                {
                    moduleID = dt.Rows[0]["ModuleID"].ToString();//模块ID
                    moduleName = dt.Rows[0]["ModuleName"].ToString();//模块名称
                    remark = dt.Rows[0]["Remark"].ToString();//备注
                }
            }
            catch (Exception e)
            {
                throw e;
            }

            return dt;
        }
        #endregion

        #region 根据条件获取查询SQL语句 public string GetSqlString(string condition)
        /// <summary>
        ///GetSqlString(string condition) 根据条件获取查询SQL语句
        ///</summary>
        public string GetSqlString(string condition)
        {

            //生成Sql查询语句
            StringBuilder Sql = new StringBuilder();
            Sql.Append(" SELECT ");
            Sql.Append(" ModuleID,ModuleName, Remark ");
            Sql.Append(" FROM Module ");
            if (condition != null && condition != "")
            {
                Sql.Append(" WHERE " + condition);
            }

            //返回
            return Sql.ToString();
        }
        #endregion



        #endregion

    }
}