Simple function that builds a row filter query via the parameters in the querystring. Checks to ensure that the key matches a column in the dataviewer.

DataViewRowFilterViaQueryStrings.cs

private void getSearchQueryFromQueryString()
        {
            try
            {
                //String for row query.
                StringBuilder sb = new StringBuilder();

                //Get all the information in the query strings.
                NameValueCollection querystrings = Request.QueryString;
                
                //Is there is any parameters provided?
                if (querystrings.HasKeys())
                {
                    //Loop through each.
                    foreach(string key in querystrings.Keys)
                    {
                        string value = querystrings[key];

                        bool columnExistInData = false;

                        //Does this key match a column in the data viewer?
                        foreach (DataColumn dc in dv.Table.Columns)
                        {
                            if (dc.ColumnName.ToString().Trim().ToLower() == key.Trim().ToLower())
                            {
                                //Match!
                                columnExistInData = true;
                                break; //Get out of the loop.
                            }
                        }

                        //Make sure both are clean and exist.
                        if (!String.IsNullOrEmpty(key) && !String.IsNullOrEmpty(value) && columnExistInData)
                        {
                            //If they both have value to them. Check if the value is a string or int.
                            int result;
                            bool isInt = int.TryParse(value, out result);
                            
                            //Check if we need a transition word. 
                            if (sb.Length > 0)
                            {
                                sb.Append(" AND ");
                            }
                            
                            //Is it an integer or string?
                            if (isInt)
                            {
                                //Value is a INT.
                                sb.Append("[" + key + "] = " + value);
                            }
                            else
                            {
                                //Value is a string.
                                sb.Append("[" + key + "] like '*" + value + "*'");
                            }
                        }
                    }

                    //set the filter. Make dv.RowFilter = filterQuery later on in code after calling this function.
                    filterQuery = sb.ToString();
                }
            }
            catch (Exception ex)
            {
                //Something went wrong.
            }   
        }