Question

In SQL, which command is used to SELECT only one copy of each set of duplicable rows

(a) SELECT DISTINCT

(b) SELECT UNIQUE

(c) SELECT DIFFERENT

(d) All of the Mentioned

The question was posed to me in final exam.

My doubt is from Structured Query Language topic in portion SQL Basics of Oracle

Answer 1

Correct option is (a) SELECT DISTINCT

The best explanation: The keyword allows us to grab all information from a column (or columns) on a table. This, of course, necessarily means that there will be redundancies. What if we only want to select each distinct element? This is easy way to accomplish in SQL. All we need to do is that to add  after  The syntax is:SELECT DISTINCT column_name FROM table_name;.