C#利用数据库相关知识点设计实现图书查询功能

Question

请问各位老师如何实现这个功能😭

Answer 1

    private void 图书查询_Load(object sender, EventArgs e)
    {
        SqlDataReader dr = SqlHelper.ExecuteReader(CommandType.Text, "Select ClassName From tb_BookClass", null);
        while (dr.Read())
        {
            comboBox1.Items.Add(dr["ClassName"].ToString());
        }

        DataSet ds = SqlHelper.GetDataSet(CommandType.Text, "select * from tb_Book");
        dataGridView1.DataSource = ds.Tables[0];
    }

    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        DataSet ds = SqlHelper.GetDataSet(CommandType.Text, "select * from tb_Book where BookClass=@BookClass", new SqlParameter("@BookClass", comboBox1.Text));
        dataGridView1.DataSource = ds.Tables[0];
    }