Question at position 45 COUNT(*) tallies only those rows that contain a value, while COUNT counts all rows.TrueFalseSingle choice
A
True
B
False

Question

Question at position 45 COUNT(*) tallies only those rows that contain a value, while COUNT counts all rows.TrueFalse

BlackTom AI · Accepted Answer

Here is the evaluation of each choice based on the statement given and how COUNT and COUNT(*) actually behave.
Option 1: 'True' — This would claim that COUNT(*) tallies only those rows that contain a value, and that COUNT tallies all rows. In reality, COUNT(*) counts every row in the result set, regardless of whether any columns contain null values. It does not require any column to have a non-null value. So this option misstates the behavior of COUNT(*).
Option 2: 'False' — This correctly states that COUNT(*) tallies all rows in the result set, whereas COUNT (typically used as COUNT(column) or COUNT(expression)) counts only the rows where the specified column or expression evaluates to a non-null value. If a column has nulls, those rows are not counted by COUNT(column). This aligns with standard SQL semantics and clarifies the common confusion between the two forms.
Additional nuance: if you write COUNT(*) vs COUNT(*) over a filtered set, the counts reflect the rows present after filtering; but the key distinction remains that COUNT(*) includes all rows, while COUNT(column) excludes rows where column is null. When using COUNT(*) and COUNT(1) or COUNT(*) with a constant expression, the results are effectively the same since the expression is never null.
In summary, the statement is false because COUNT(*) does not require a value in any column, and COUNT only counts non-null occurrences of the specified column or expression.

Question at position 45 COUNT(*) tallies only those rows that contain a value, while COUNT counts all rows.TrueFalseSingle choice

Similar Questions

Which SQL statement will provide the answer to how many staff are in the staff table?

If a trip has no bookings, then COUNT(booking_id) after a LEFT JOIN will return NULL for that trip.

COUNT(*) and COUNT(review_id) always return the same value.

Which of the following questions is answered by the SQL statement? SELECT COUNT (Product_Description) FROM Product_T;

Question at position 50 COUNT(*) tallies only those rows that contain a value, while COUNT counts all rows.TrueFalse

More Practical Tools for Students Powered by AI Study Helper

Homework AI Solver

Stylized AI Paper Writer

Plagiarism Checker Assistant

Citation AI Academic Writing Tool

In-Class Translation Assistant

AI Note Generator

AI Quiz Answers

Past Exam Questions from University Test Bank

Smart Practice Assistant

Adaptive Practice

Making Your Study Simpler