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

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In this question, we must evaluate the truth of the statement about COUNT(*) and COUNT.
Option 1: True. This is not correct because COUNT(*) does not count only rows with a value; it counts every row in the result set, including rows where all columns are NULL. The only thing COUNT(*) excludes is rows that are filtered out by the WHERE clause or that are in a different grouping, not based on NULL values.
Option 2: False. This option aligns with how SQL aggregate functions work: COUNT(*) counts all rows, regardless of NULLs in any column, whereas COUNT(column) counts only the rows where that specific column is not NULL. For example, in a table with some NULL values in a given column, COUNT(*) would include those rows, but COUNT(column) would not count the rows where column is NULL.
Additional clarification: The distinction matters when you want to know the total number of rows versus the number of non-NULL entries for a particular column. If you want the total row count, use COUNT(*). If you want the count of non-NULL values in a column, use COUNT(column_name). Finally, remember that the NULL semantics are a key part of understanding these aggregates, so accounting for NULLs is essential in interpreting the results correctly.

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

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