5.6

COUNT(column_name) and COUNT(*)

How They Are Different

COUNT(column_name) and COUNT(*)

  • COUNT(*) is the only aggregate function that counts rows with null values.
  • When you specify a count based on a specific column, null values will not be counted.

Code Sample:

USE bike;
SELECT COUNT(phone), COUNT(*) 
FROM CUSTOMER

Output:

ag_06.png

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