Which function adds the values in a column?

Which function adds the values in a column?

• A. sum
• B. count
• C. max
• D. min

Answer: (A)

The main idea is using an aggregate function that totals numeric values by adding them together. When you want the overall total of a column, the function that adds each value across all rows provides that total. It’s different from the others: counting tells you how many rows or non-null values there are, not their sum; finding the maximum returns the largest value; finding the minimum returns the smallest. This sum function ignores NULLs in the calculation, so missing values don’t affect the total, though if every value is NULL the result is NULL. You can use it to get a single total or to compute totals within groups, for example by pairing it with GROUP BY to get totals per category.

The main idea is using an aggregate function that totals numeric values by adding them together. When you want the overall total of a column, the function that adds each value across all rows provides that total. It’s different from the others: counting tells you how many rows or non-null values there are, not their sum; finding the maximum returns the largest value; finding the minimum returns the smallest. This sum function ignores NULLs in the calculation, so missing values don’t affect the total, though if every value is NULL the result is NULL. You can use it to get a single total or to compute totals within groups, for example by pairing it with GROUP BY to get totals per category.