At present, support of training by various Learning Management Systems (LMS) is normally part of education at many universities. In this paper, the author deals with a Data Base System (DBS) component which is used for support of database skills testing of students. Testing is focused on Structured Query Language, especially statements of Data Manipulation Language, and relational algebra. DBS component consists of subcomponents which are realized as plugins to Learning Management System (LMS) Moodle. DBS component also enforces designed security policy and supports of errors processing.