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;

Respuesta :

Answer:

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.

The query that should be used for a unique value is option d.

The following information should be considered:

  • The query listed the unique value for V_CODE arise from the PRODUCT table.
  • Option A is wrong as it used ONLY keyword that does not represent the unique value.
  • Option B is wrong as it is constraint where the columns values are considered to be unique.
  • Option C is wrong as DIFFERENT does not represent the keyword.
  • Option D is right as query applied SELECT and DISTINCT that represent different values.

Therefore we can conclude that the correct option is D.

Learn more: brainly.com/question/22701930