Three Dimensional Dictionary in C#

Suppose we need to build a collection of Postal Code in which each postal code contains a collection of Cities. Each City is itself a collection of Street Addresses and each Street contains all the residents and their personal record. We are going to make this whole collection with Dictionary collection which is one of the best data structure from searching efficiency perspective. So our  “Three dimensional dictionary collection” will look like:

Postal Code -> City –> Street Addresses -> Resident’s Records -> SSN, Name, Age, Gender, Occupation

In C#, we can implement the above collection in following way:

class ThreeDimensionalDictionaryDemo

    {

        public Dictionary<string, Dictionary<string, Dictionary<string, List<ResidentRecord>>>> PeopleCollection = new Dictionary<string, Dictionary<string, Dictionary<string, List<ResidentRecord>>>>();

        public void AssemblePersonRecordByPostalCode()

        {

            try

            {

                // A data record file "RecordsFile.txt" is read.

                StreamReader oStreamReader = new StreamReader("RecordsFile.txt");

                string line;

                string postalCode;

                string city;

                string streetAddress;

                ResidentRecord oRecord;

                while ((line = oStreamReader.ReadLine()) != null)

                {

                    // In records file, we keep one person's record in one line and data fields are seperated by TAB

                    // For example:

                    // 933467543    John Smith   24  Male    Business    21093   Timonium    2311 York Rd Suit # 44

                    string[] parsedItem = line.Split('\t');

                    // Retrieving data fields

                    oRecord.SSN = parsedItem[0];

                    oRecord.Name = parsedItem[1];

                    oRecord.Age = Convert.ToInt16(parsedItem[2]);

                    oRecord.Gender = parsedItem[3];

                    oRecord.Occupation = parsedItem[4];

                    postalCode = parsedItem[5];

                    city = parsedItem[6];

                    streetAddress = parsedItem[7];

                    // If we get an already existing Postal Code

                    if (PeopleCollection.ContainsKey(postalCode))

                    {

                        //  If we get an already existing City

                        if (PeopleCollection[postalCode].ContainsKey(city))

                        {

                            //  If  we get an already existing StreetAddress

                            if (PeopleCollection[postalCode][city].ContainsKey(streetAddress))

                            {

                                // Person's record is added into list

                                PeopleCollection[postalCode][city][streetAddress].Add(oRecord);

                            }

                            //  If we get a new StreetAddress

                            else

                            {

                                // Street Address is added and value part is newed up

                                PeopleCollection[postalCode][city].Add(streetAddress, new List<ResidentRecord>());

                                // Person's record is added into list

                                PeopleCollection[postalCode][city][streetAddress].Add(oRecord);

                            }

                        }

                        //  If we get a new city 

                        else

                        {

                            // City is added and value part is newed up

                            PeopleCollection[postalCode].Add(city, new Dictionary<string, List<ResidentRecord>>());

                            // Street Address is added and value part is newed up

                            PeopleCollection[postalCode][city].Add(streetAddress, new List<ResidentRecord>());

                            // Person's record is added into list

                            PeopleCollection[postalCode][city][streetAddress].Add(oRecord);

                        }

                    }

                    // If we get a new postal code

                    else

                    {

                       

                        // Postal code is added and value part is newed up

                        PeopleCollection.Add(postalCode, new Dictionary<string, Dictionary<string, List<ResidentRecord>>>());

                        // City is added and value part is newed up

                        PeopleCollection[postalCode].Add(city, new Dictionary<string, List<ResidentRecord>>());

                        // Street Address is added and value part is newed up

                        PeopleCollection[postalCode][city].Add(streetAddress, new List<ResidentRecord>());

                        // Person's record is added into list

                        PeopleCollection[postalCode][city][streetAddress].Add(oRecord);

                    }

                }

            }

            catch (Exception e)

            {

                throw e;

            }

        }                  

    }