Which query is used to list a unique value for V_CODE, where the list will produce only a list of those values that are different from one another? a. SELECT ONLY V_CODE FROM PRODUCT;
b. SELECT UNIQUE V_CODE FROM PRODUCT;
c. SELECT DIFFERENT V_CODE FROM PRODUCT;
d. SELECT DISTINCT V_CODE FROM PRODUCT;

d. SELECT DISTINCT V_CODE FROM PRODUCT;

Explanation:

The query basically lists a unique value for V_CODE from PRODUCT table.

Option a is incorrect because it uses ONLY keyword which does not use to list a unique value for V_CODE. Instead ONLY keyword is used to restrict the tables used in a query if the tables participate in table inheritance.

Option b is incorrect because it is a constraint that ensures that all values in a column are unique.

Option c is incorrect because DIFFERENT is not a keyword

Option d is correct because the query uses SELECT statement and DISTINCT is used to select only distinct or different values for V_CODE.

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