COUNT

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COUNT(f)
EngineOKAlternative
ingresYes
mysqlYes
oracleYes
postgresYes
sqlserverYes

COUNT

COUNT(column_name) finds the number of non-null values in a column. COUNT(*) also counts the null values.

COUNT is an aggregate function it is normally used with GROUP BY.

  SELECT region, COUNT(name)
    FROM bbc
   GROUP BY region 

With a GROUP BY region statement each region shows up just once. The COUNT column gives the number of countries for each region.

SELECT region, COUNT(name)
  FROM bbc
 GROUP BY region

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