【重构】C#——增删改查语句汇总

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前言

重构过程中，D层来实现接口层的方法，进行的是直接操作数据库，针对数据的插入，更新，删除，查找 四种操作，主要是用来和数据库进行直接交互。每一种数据操作都有固定的格式，下面就对增删改查这四种操作格式进行一个总结，每一种都举栗子来说明。

内容

1、插入

//插入记录到onwork表中
        public DataTable Insert(Entity.OnWorkInfo onwork,Entity.UserInfo UserInfo)
        {
            //查询是否有信息
            SqlParameter[] sqlParams = { new SqlParameter("@userID", UserInfo.UserID), new SqlParameter("@Password", UserInfo.Password) };
            string sql = @"SELECT * FROM [User_Info] WHERE userID=@UserID and PWD =@Password";
            DataTable table = sqlHelper.ExecuteQuery(sql, sqlParams, CommandType.Text);

            //如果可以查到当前卡号，将当前卡号插入到Onwork表中
            if (table.Rows.Count != 0)
            {
                SqlParameter[] param = { new SqlParameter("@UserID",onwork.userID),
                                    new SqlParameter("@level",onwork.level),
                                    new SqlParameter("@loginDate",onwork.loginDate)
                                    };
                string sql2 = @"Insert into OnWork_Info(UserID,level,loginDate)values(@UserID,@level,@loginDate) ";
                DataTable table2 = sqlHelper.ExecuteQuery(sql2, param, CommandType.Text);
                return table2;
            }
            return table;                        
        }

2、查找

        //判断卡号是否注册
        public DataTable Student(Entity.studentInfo student)
        {
            SQLHelper sqlhelper = new SQLHelper();
            SqlParameter[] param = {new SqlParameter("@cardno",student.cardno)};
            string sql = @"select * from student_Info where cardno=@cardno";
            DataTable table = sqlhelper.ExecuteQuery(sql,param,CommandType.Text);
            return table;
        }

3、删除

//删除记录
        public DataTable Delete(Entity.OnWorkInfo onwork)
        {
            SQLHelper sqlHelper = new SQLHelper();
            SqlParameter[] param = {new SqlParameter("@UserID",onwork.userID)};
            string sql = @"delete from OnWork_Info where UserID=@UserID";
            DataTable table = sqlHelper.ExecuteQuery(sql,param,CommandType.Text);
            return table;
        }

4、更新

//更新基本数据表
        public DataTable BasicInfoEdit(Entity.BasicDataInfo basicdatainfo)
        {
            SQLHelper sqlhelper = new SQLHelper();
            SqlParameter[] sqlpara = {new SqlParameter("@Rate",basicdatainfo.rate),
                                      new SqlParameter("@tmpRate",basicdatainfo.tmpRate),
                                      new SqlParameter("@unitTime",basicdatainfo.unitTime),
                                      new SqlParameter("@limitCash",basicdatainfo.limitCash)                                    
                                     };
            string sql = @"update BasicData_Info set Rate=@Rate,tmpRate=@tmpRate,unitTime=@unitTime,limitCash=@limitCash";
            
            DataTable table = sqlhelper.ExecuteQuery(sql,sqlpara ,CommandType.Text);
            return table;
        }