I've found the *Big Surprise* which comes from my side. What I thought is an old database (generated by java application using BaseX library version 7.3.1) is actually an updated database by java application using BaseX library version 8.6.7.
This data for some reasons has missing data (maybe someone removed them) and when I tried to copy this database to the java application using BaseX library version 7.3.1 (I thought it can open this database and query normally), but actually, it cannot read and instead it drop this database and create a new one with default data. That causes the difference between version 8.6.7 and 7.3.1 in my first message (one is a database with missing data and one is a newly created database). I've noticed that after I tried to use BaseX GUI jar (version < 8.6.1) to open this database and it said "The database format has changed; please use a newer version" which showed that I don't have a database in version 7.3.1 but much higher than it. Thanks for all your support :-), this helped me to learn more about BaseX.
