C# 带日期和字符串条件的select语句的正确语法是什么？

这是我的密码

    class CLSAttend
{
    DAL.DataAccessLayer op = new DAL.DataAccessLayer();
    public DataTable loadhooodor(string heUsers)
    {
        DateTime today = DateTime.Today;
        DataTable loadhooodor = new DataTable();
        string procedure = "select * from HoodoorEnseraf where heDate= @today and  heUsers= @heUsers";
        OleDbParameter[] param = new OleDbParameter[2];
        param[0] = new OleDbParameter("@today", OleDbType.Date);
        param[0].Value = today;
        param[1] = new OleDbParameter("@heUsers", OleDbType.VarChar);
        param[1].Value = heUsers;
        loadhooodor=op.selectData(procedure, param);
        return loadhooodor;
    }

}

并参加表格

            dataGridView1.DataSource = attend.loadhooodor(heUser.Text);

但是仍然没有从表中获取任何数据到我的datagridview，您需要调用

dataGridView1.DataBind（）