Language: C# DB: Access (So, OleDbDataAdapter)

Context:
--------

My current project, I'm building a sort of sql query builder. Depending on what the user selects from a drop down list, an sql command can look like this, not sure if it's relevant to the question though [] are columns/table () are drop down optionals, the parenthesis aren't actually there: 

```
Select * From [db] where [Date] (between) @value1 and @value2 AND [ID] (=) @ID AND [Usd] (=) @Usd

```

Well, you get the idea.

I run this through the following code:

```
sbuilder = new StringBuilder();

sbuilder.Append("Select * FROM ").Append(Current_Table).Append(" WHERE ");

using (OleDbConnection connection = new OleDbConnection(Con))
        {
            connection.Open();
            string query = sbuilder.ToString();
            OleDbDataAdapter da = new OleDbDataAdapter(query, connection);
            da.SelectCommand.Parameters.Clear();

//some code to build the string, AND build the select parameters, here's the important one though

            da.SelectCommand.Parameters.AddWithValue("@USD", Convert.ToDouble(FilterUSD.Text));
            DataTable dt = new DataTable();
            da.Fill(dt);
            DGVMain.DataSource = dt;
            connection.Close();
        }

```

My problem: 

When I retrieve the values, as you expect, they must match the value of FilterUSD.Text, so when a user searches for 12, and the DB contains 12.31251, he will return 0 rows. How do I make it so that when the parameter is 12, it would return all values that have a base value 12 and any following decimal values. The examples i've looked at online seem to suggeset using an sql data reader, and retrieving the values into a variable Double. 

How do I proceed in the context of using a data adapter, as I am currently using, to fill the datatable? (and later, a datagridview)

My hunch is I will have to make use of the parameters of my select command.

Found this link, I dont know how to convert it for my use though as a datatable: [Read decimal from SQL Server database](https://stackoverflow.com/questions/35185273/read-decimal-from-sql-server-database)