Preparation of test demo database and tuning of SQL commands

This bachelor work deals with projecting and implementation of the demo test database, which is used for training work with relational databases. A set of educational queries submissions which enable practising query language SQL (Structured Query Language) is one part of the work. There is a well-arranged table of correct output from data test for all of queries allowing to check correct query setting. In the theoretical part there is a short mention about the principles of databases projecting and data modelling, especially about the "Three schema approaches"