Answer Happy

3. Consider the following relational schema and assume that the tables and necessary constraints are created accordingly. Also, assume that the three tables have no rows so far: Event EventID EventName Research Topic TopicID TopicName Area Covers EventID WebLink TopicID Date EventCount We want to insert the record ('El', 'T1') into the Covers table. In order to perform this task successfully what SQL code we need, and in which order it must be executed? Assume all attributes other than PK may be null and all data types are varchar (20). [3 marks]
5. Again, consider the schema given in Q3 and assume that the tables and necessary constraints are created accordingly. If we execute the following code and no error happens what does that indicate in reference to the FK constraint from Covers to ResearchTopic? Discuss at least one possibility. [1 mark] DELETE FROM WHERE COVERS TOPICID = 'T2' ;