MySQL Queries with Conditions: Perform MySQL queries with simple conditions

This class can perform MySQL queries with simple conditions.

It can connect to a MySQL server using MySQLi and execute common queries. Currently it can execute a SQL query of type:

- SELECT on a table with a condition to match one table field, to match two fields, to match one field with two distinct values
- INSERT on a table with given field values
- UPDATE on a table with matching one field value