Difference between revisions of "COUNT()"
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Revision as of 03:34, 7 December 2012
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
