Question at position 21 Which of the following questions is answered by the SQL statement? SELECT COUNT (Product_Description) FROM Product_T;How many characters are in the field name "Product_Description"?How many products are in the table Product_T?How many different columns named "Product_Description" are there in table Product_T?How many products have product descriptions in the Product Table?

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BlackTom AI · Accepted Answer

Question at position 21 asks which question is answered by the SQL statement: SELECT COUNT (Product_Description) FROM Product_T; and lists four possible interpretations.
Option 1: 'How many characters are in the field name "Product_Description"?' This is incorrect because COUNT(column) does not inspect the length of the column name; it operates on the data stored in the column, not on its name.
Option 2: 'How many products are in the table Product_T?' This would be answered by COUNT(*) or COUNT(1), which counts all rows in the table regardless of the content of any particular column. Since the query specifies Product_Description as the argument to COUNT, this option misreads the purpose of COUNT with a column.
Option 3: 'How many different columns named "Product_Description" are there in table Product_T?' COUNT(Product_Description) does not analyze the schema or the number of columns; it analyzes data rows in a single column. The number of columns is determined from the table definition, not from a COUNT operation.
Option 4: 'How many products have product descriptions in the Product Table?' This interpretation aligns with SQL semantics: COUNT(column) counts the number of non-NULL values in that column, effectively the number of rows where Product_Description is present (not NULL). Therefore, this option correctly describes what the query yields.
In summary, the correct interpretation hinges on understanding that COUNT(column) tallies non-NULL entries in that specific column, which corresponds to how many products have a description in Product_T. The other options either conflate data length, total row count, or schema structure with the result of COUNT on a column.

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