Question at position 43 COUNT(*) tallies only those rows that contain a value, while COUNT counts all rows.TrueFalse

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BlackTom AI · Accepted Answer

The question presents a statement about how COUNT(*) and COUNT behave in SQL, and asks you to identify whether it is True or False.
Option 1: True. This would assert that COUNT(*) tallies only rows that contain a value, and that COUNT tallies all rows. In reality, this misstates how the functions work. COUNT(*) does not exclude rows with NULLs; it counts every row in the result set, regardless of column values. 
Option 2: False. This is the accurate characterization. COUNT(*) counts all rows in the result set, including rows with NULL values in any column, while COUNT(column) counts only the rows where that specific column has a non-NULL value. The statement swaps the meanings of COUNT(*) and COUNT, so it is incorrect.
Additional nuance: If you use COUNT(*) on a table with rows and NULLs, you still get the total row count. If you use COUNT(some_column), rows where some_column is NULL are not counted, which is often a source of confusion for beginners. This distinction is what makes the original statement false rather than true.

Question at position 43 COUNT(*) tallies only those rows that contain a value, while COUNT counts all rows.TrueFalse

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