Question

当我从数据库中选择所有数据并显示它时，它工作正常。但是，当我想专门显示数据库中的某些数据时，就会出现该错误。（System.Data.OleDb.OleDbException：'未为一个或多个必需参数提供值。）

  private void button1_Click(object sender, EventArgs e)
  {
   string selectoledb = "Select * from items where Categories=Fitems";
   command = new OleDbCommand(selectoledb, connection);
   da = new OleDbDataAdapter(command);

    DataTable table = new DataTable();
    itemstxt.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill;
    itemstxt.RowTemplate.Height = 120;
    itemstxt.AllowUserToAddRows = false;

    da.Fill(table);

    itemstxt.DataSource = table;

    DataGridViewImageColumn imageColumn = new DataGridViewImageColumn();
    imageColumn = (DataGridViewImageColumn)itemstxt.Columns[3];
    imageColumn.ImageLayout = DataGridViewImageCellLayout.Stretch;

     DataGridViewButtonColumn button = new DataGridViewButtonColumn();
     button.HeaderText = "Buttons";
     button.Name = "button";
     button.Text = "Add to cart";
     button.UseColumnTextForButtonValue = true;
     itemstxt.Columns.Add(button);


     da.Dispose();

    }

Answer 1

您需要将参数添加到您的选择

string selectoledb = "Select * from items where Categories=@Fitems";
command.Parameters.Add("@Fitems", SqlDbType.Varchar).Value = Fitems.Text; //or value you want to filter

尝试从数据库到datagridview显示特定数据时收到此错误

1 个答案: