Multiple choice

All of the following can only be used with numeric data types except _____.

  1. AVG

  2. COUNT

  3. SUM

  4. STDDEV

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

COUNT is the only aggregate function listed that works with all data types (numeric, character, date). AVG, SUM, and STDDEV are mathematical functions that only work with numeric data. COUNT(*) counts rows, while COUNT(expression) counts non-null values regardless of data type.