Pass dynamic number of paramters?

Question

I am making a .NET 1.0 style query. I have a requirement to pass any number of "states" as a filter on my query. So, how do I make a query where the number of states is unknown?....aside from putting in 52 parameters and handling nulls on them all?
Current code:
public List<EventLocation> GetEventLocationsByState(string state)
List<EventLocation> eventLocations = new List<EventLocation>();
string sql = string.Empty;
OracleCommand command = null;
int rowsEffected = 0;
// Query V_LOCATION_INFO table
m_connection.Open();
sql += "SELECT EVE_RID, EVE_EVENT_CODE, LOC_NAME, LOC_ST_ADDRESS, LOC_ST_CITY, STATE, ";
sql += " LOC_ST_ZIP_CODE, LOC_PHONE ";
sql += "FROM V_LOCATION_INFO ";
sql += "WHERE STATE = :pState ";
command = new OracleCommand(sql, m_connection);
command.CommandType = CommandType.Text;
// IN - State
// Execute
OracleDataReader reader = command.ExecuteReader();
while (reader.Read())
EventLocation eventLocation = new EventLocation();
// OUT - Event ID
eventLocation.EventID = Convert.ToInt64(reader["EVE_RID"]);
// OUT - Event Code
if (reader["EVE_EVENT_CODE"] != DBNull.Value)
eventLocation.EventCode = reader["EVE_EVENT_CODE"].ToString();
// OUT - Location Name
if (reader["LOC_NAME"] != DBNull.Value)
eventLocation.LocationName = reader["LOC_NAME"].ToString();
// OUT - Location Street Address
if (reader["LOC_ST_ADDRESS"] != DBNull.Value)
eventLocation.LocationStreetAddress = reader["LOC_ST_ADDRESS"].ToString();
// OUT - Location City
if (reader["LOC_ST_CITY"] != DBNull.Value)
eventLocation.LocationCity = reader["LOC_ST_CITY"].ToString();
// OUT - Location State
if (reader["STATE"] != DBNull.Value)
eventLocation.EventCode = reader["STATE"].ToString();
// OUT - Location Zip Code
if (reader["LOC_ST_ZIP_CODE"] != DBNull.Value)
eventLocation.LocationZipCode = reader["LOC_ST_ZIP_CODE"].ToString();
// OUT - Location Phone Number
if (reader["LOC_PHONE"] != DBNull.Value)
eventLocation.LocationPhone = reader["LOC_PHONE"].ToString();
eventLocations.Add(eventLocation);
++rowsEffected;
m_connection.Close();
if (rowsEffected == 0)
return null;
return eventLocations;
}

Answer 1

See also How to use OracleParameter whith the IN Operator of select statement