QTxtDB: Manage a database stored in text files

This class can be used to manage a database on which the tables are stored as text files.

It can create tables that are stored in separate files. Each table field is made of text of length defined at table creation time.

The class can insert new records by adding a new data at the end of the table file with text of new record field values.

It can also update a record with new values for the table fields.

The class can also delete a record with a given row number by marking it as deleted.

It can also search and retrieve records that have a given search text.

The class can also convert the data in a table to a file in the CSV format.

The class comments are in Chinese.