使用填充的组合框值在where子句中使用以过滤结果

Question

Just another problem.

I am trying to populate a data table with just a combo box when a user selects a crop type.

When the user selects a crop from the dropdown ie wheat, barley and oats for example I want that to be added to a view so return the values in the database.

With the crop selected then it will only show the fields that have that crop planted and the costs associated with it.

var select = "SELECT * from fieldCostOverview where CropType = ('" + cmbCrops.SelectedItem.ToString + "')";

//var c = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=H:\School\Magee\Project\Programme\Farm Costs\Farm Costs\farmCosts.mdf;Integrated Security=True"); // Your Connection String here
var c = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=F:\School\Magee\Project\Programme\Farm Costs\Farm Costs\farmCosts.mdf;Integrated Security=True");
var dataAdapter = new SqlDataAdapter(select, c);

var commandBuilder = new SqlCommandBuilder(dataAdapter);
var ds = new DataSet();
dataAdapter.Fill(ds);
dgFieldDetails.ReadOnly = true;
dgFieldDetails.DataSource = ds.Tables[0];

the value in the combo box will then show me only the fields and the details of that crop type.

Any advice or tips?

Answer 1

使用SelectedValue

  var select = "SELECT * from fieldCostOverview where CropType = ('" +      cmbCrops.SelecteValue + "')";