Difference between revisions of "COUNT()"

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==See Also==
 
==See Also==
[[SQL Aggregate Functions|AGGREGATES]], [[AVG()]], [[SQL MAX()|SQL MAX()]], [[SQL MIN()|MIN()]], [[SQL SELECT|SELECT]], [[SUM()]]
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[[SQL Aggregate Functions|AGGREGATES]], [[AVG()]], [[SQL MAX()|MAX()]], [[SQL MIN()|MIN()]], [[SQL SELECT|SELECT]], [[SUM()]]
  
  

Latest revision as of 17:16, 22 December 2009

Purpose

Returns the number of rows in a SELECT statement query


Syntax

COUNT(* | [DISTINCT] <expr>)


See Also

AGGREGATES, AVG(), MAX(), MIN(), SELECT, SUM()


Description

Returns the number of rows in the query. If you specify DISTINCT, then only the rows which are unique in <expr> are counted. Specifying <expr> on its own returns the number of rows from the query for which <expr> is not NULL. If you specify the asterisk (*), then all rows are counted.


Example

// Get a count of all rows in the accounts table.
SELECT COUNT(*) Total FROM accounts
 
// Get a count of jobs
SELECT COUNT(jobs) Jobs FROM employee
 
// Get a count of distinct rows for jobs
SELECT COUNT(DISTINCT jobs) Jobs FROM employee


Products

Recital Server, Recital