In-memory SQL-like Database
Problem Statement
The objective is to design and implement an in-memory SQL-like database, which should support the following set of operations/functionality:

1. It should be possible to create, update or delete tables in a database.
2. A table definition comprises columns which have types. They can also have constraints
3. The supported column types are string and int.
4. Users can give the constraint of string type that can have a maximum length of 20 characters.
5. Users can give the constraint of int type that can have a minimum value of 1024.
6. Support for mandatory fields (tagging a column as required)
7. It should be possible to insert records in a table.
8. It should be possible to print all records in a table.
9. It should be possible to filter and display records whose column values match a given value.