mysql - “SELECT * FROM book WHERE year=wyear AND account >= waccount1 AND account <= waccount1”

Question

几天来，我一直在努力显示数据集中表中的数据。当我不在 WHERE 中放置条件时，它会显示完整的表，但只需要表中满足条件的行。如果有更快查看的建议。多谢。

myConnectionString = pwput;
MySqlConnectionconpara = new MySql.Data.MySqlClient.MySqlConnection();
conpara.ConnectionString = myConnec DataSetionString;
try
{
    conpara.Open();
    if (conpara.State == ConnectionState.Open)
    {
        string waccoun1 = wnalog1.ToString();
        string waccoun2 = wnalog2.ToString();
        stringnupita = "SELECT * FROM book WHERE year=wyear AND account >= 
        waccount1 AND account <= waccount1";
        MySqlCommandcmdnal = new   MySqlCommand(nupita,conpara); 
        MySqlCommand(nupita,conpara);cmdnal.Parameters.AddWithValue("@year", 
        wyear);
        MySqlDataAdapte radda = new MySqlataAdapter(cmdnal);
        MySqlCommandBuildercbb = new MySqlCommandBuilder(adda);
        DataSet dsd = new DataSet();
        adda.Fill(dsd, "book");
        conpara.Close();
        if (dsd != null)
        {
            dataGridView1.DataSource = dsd;
            dataGridView1.DataMember = "book";
            Font = new System.Drawing.Font("Arial Unicode", 7);
            dataGridView1.Font = Font;
        {

Answer 1

您需要使用如下参数:

...

stringnupita = "SELECT * FROM book WHERE year=@year AND account >= 
        @waccount1 AND account <= @waccount2";
  MySqlCommand(nupita,conpara);cmdnal.Parameters.AddWithValue("@year", 
        wyear);
  MySqlCommand(nupita,conpara);cmdnal.Parameters.AddWithValue("@waccount1", 
        waccount1);
MySqlCommand(nupita,conpara);cmdnal.Parameters.AddWithValue("@waccount2", 
            waccount2);
    ...