![]() |
SQL-J Language Reference
|
Reference Manual |
COUNTCOUNT is an aggregate function that counts the number of rows accessed in an expression (see Aggregates (Set Functions)). COUNT is allowed on all types of expressions, even those that evaluate to Java data types. SyntaxCOUNT ( [ DISTINCT | ALL ] Expression ) The DISTINCT qualifier eliminates duplicates. The ALL qualifier retains duplicates. ALL is assumed if neither ALL nor DISTINCT is specified. For example, if a column contains the values 1, 1, 1, 1, and 2, COUNT(col) returns a greater value than COUNT(DISTINCT col). Only one DISTINCT aggregate expression per SelectExpression is allowed. For example, the following query is not allowed:
-- query not allowed An Expression can contain multiple column references or expressions, but it cannot contain another aggregate or subquery. If an Expression evaluates to NULL, the aggregate is not processed for that value. The resulting data type is LONGINT. COUNT Examples
-- Count the number of distinct last names AND the total number
-- Count the number of countries in each region, |
|
![]() Cloudscape Version 3.6 For information about Cloudscape technical support, go to: www.cloudscape.com/support/.Copyright © 1998, 1999, 2000 Informix Software, Inc. All rights reserved. |