Explanation:Not null constraint removes the tpules of null values. 6. Using the ______ clause retains only one copy of such identical tuples.
A. Null
B. Unique
C. Not null
D. Distinct
Answer:A
Explanation:Not null constraint removes the tpules of null values. 6. Using the ______ clause retains only one copy of such identical tuples.
A. Null B. Unique C. Not null D. Distinct
Explanation:Unique is a constraint. 7. Create table employee (id integer,name varchar(20),salary not null);