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date
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string
Compatibility
COUNT(f)
Engine OK Alternative
mysql yes
oracle yes
postgres yes
sqlserver yes

COUNT

COUNT finds the number of non-null values in a column.

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.

Results
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