Is possible to insert data into database using hash table concepts?

Hashtable is an older collection that is essentially obsoleted by the Dictionary in .NET framework. Also, Hashtable has worse performance than Dictionary.

Anyway, here is the sample code to maintain the data in hash table.

Hashtable hashtable = new Hashtable();
hashtable[1] = "One";
hashtable[2] = "Two";
hashtable[13] = "Thirteen";

foreach (DictionaryEntry entry in hashtable)
{
    Console.WriteLine("{0}, {1}", entry.Key, entry.Value);
}