//調(diào)用存儲過程判斷學(xué)生是否已經(jīng)登錄。
    public int StudentIfLogin(string stuid)
    {
        SqlCommand cmd = new SqlCommand("StudentIfLogin", stuConn);
        cmd.CommandType = CommandType.StoredProcedure;

        //給存儲過程添加參數(shù)
        SqlParameter stu = new SqlParameter("@StudentID", SqlDbType.NVarChar, 50);
        stu.Value = stuid;
        cmd.Parameters.Add(stu);

        SqlParameter aff = new SqlParameter("@returnvalue", SqlDbType.Int, 4);
        aff.Direction = ParameterDirection.Output;
        cmd.Parameters.Add(aff);

        cmd.ExecuteNonQuery();
       if(aff.Value!=0)
            return (int)aff.Value;
        else
            return 0;
     }

//調(diào)用存儲過程判斷老師是否已經(jīng)登錄。
    public int TeacherIfLogin(string teaid)
    {
        SqlCommand cmd = new SqlCommand("TeacherIfLogin", teaConn);
        cmd.CommandType = CommandType.StoredProcedure;

        //給存儲過程添加參數(shù)
        SqlParameter tea = new SqlParameter("@TeacherID", SqlDbType.NVarChar, 50);
        tea.Value = teaid;
        cmd.Parameters.Add(tea);

        SqlParameter aff = new SqlParameter("@returnvalue", SqlDbType.Int, 4);
        aff.Direction = ParameterDirection.Output;
        cmd.Parameters.Add(aff);

        cmd.ExecuteNonQuery();
       if(aff.Value!=0)
            return (int)aff.Value;
        else
            return 0;
}

//調(diào)用存儲過程判斷管理員是否已經(jīng)登錄。
    public int AdminIfLogin(string adminid)
    {
        SqlCommand cmd = new SqlCommand("AdminIfLogin", adminConn);
        cmd.CommandType = CommandType.StoredProcedure;

        //給存儲過程添加參數(shù)
        SqlParameter admin = new SqlParameter("@AdminID", SqlDbType.NVarChar, 50);
        admin.Value = adminid;
        cmd.Parameters.Add(admin);

        SqlParameter aff = new SqlParameter("@returnvalue", SqlDbType.Int, 4);
        aff.Direction = ParameterDirection.Output;
        cmd.Parameters.Add(aff);

        cmd.ExecuteNonQuery();
       if(aff.Value!=0)
            return (int)aff.Value;
        else
            return 0;
    }