Sorting and Limiting Results Flashcards
7 cards from real SQL practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Sorting and Limiting Results flashcards as text
How are NULL values typically sorted in PostgreSQL ascending order by default?
Answer: NULLs appear last
In PostgreSQL ascending order, NULLs are treated as larger and sort last by default.
Which clause forces NULL values to appear first in PostgreSQL?
Answer: ORDER BY col NULLS FIRST
NULLS FIRST explicitly places NULL values before non-NULL values.
Can you ORDER BY a column that is not in the SELECT list?
Answer: Yes, in most databases
Most databases allow sorting by columns not included in the SELECT list.
Which standard SQL clause limits rows using FETCH?
Answer: FETCH FIRST n ROWS ONLY
FETCH FIRST n ROWS ONLY is the ANSI SQL standard for limiting rows.
What does ORDER BY salary DESC, hire_date ASC do?
Answer: Highest salary first, ties broken by earliest hire date
Primary sort is salary descending; ties are resolved by hire_date ascending.
In MySQL, what does LIMIT 5 with no OFFSET return?
Answer: The first 5 rows
LIMIT 5 returns the first five rows of the result set.
Which is valid MySQL shorthand for OFFSET 20 LIMIT 10?
Answer: LIMIT 20, 10
MySQL's two-argument LIMIT takes offset first, then row count.