SQL - Data Management - Applications - Study to PASS the test ... 3

Question 1

COMMIT / ROLLBACK work only with data manipulation commands that add, modify, or delete table rows.

Answer 1

COMMIT / ROLLBACK

Question 2

INSERT info : inner query always executed 1st by the RDBMS.

IN : checks if an attribute value matches any value within a value list. All values in list must be the same data type.

Answer 2

INSERT / IN

Question 3

ALTER TABLE (options : ADD | MODIFY | DROP - for columns)

*** A table can be dropped only if it is not the “one” side of any relationship. If tried to drop otherwise the RDBMS will generate an error message indicating that a foreign key integrity violation has occurred.

DISTINCT : produces a list of only values that are different from one another.

Answer 3

ALTER TABLE / Etc … / DISTINCT

Question 4

COUNT(*) : returns number of total rows from the query, including rows that contain nulls.

GROUP BY : rows grouped together into smaller collections; only used with COUNT, MIN, MAX, AVG, and SUM. Also used with HAVING (replaces WHERE).

Answer 4

COUNT(*) / GROUP BY