Count « Aggregate Functions « MySQL Tutorial






  1. MySQL Tutorial
  2. Aggregate Functions
  3. Count
16.3.Count
16.3.1.COUNT()
16.3.2.COUNT(DISTINCT expr,[expr...]) (Returns a count of the number of different non-NULL values.)
16.3.3.Return the total number of rows
16.3.4.Count(*)
16.3.5.COUNT(column name)
16.3.6.Distinct count
16.3.7.Use and IF() and COUNT() to give us a total as COUNT() ignores NULL values
16.3.8.Using COUNT(*) in a table JOIN