Concatenate[
^] multiple dates(in string) into single string (separate them using comma) like,
string date1 = "1-1-2001";
string date2 = "2-2-2002";
string date3 = "3-3-2003";
string newDate = date1 + ", " + date2 + ", " + date3;
string query = "INSERT INTO TABLE_NAME (COLUMN_NAME) VALUES(newDate)";
-KR