DISTINCT Predicate

Specifies that only unique rows can appear in the result table.

Syntax

Arguments

Details

Example

Syntax

Form 1:

function DISTINCT (expression);

Form 2:

SELECT DISTINCT <select-list> FROM <table-expression>;

Arguments

function

can be any aggregate function.

expression

specifies any valid SQL expression.

See	<sql-expression>
	FedSQL Expressions

SELECT <select-list> FROM <table-expression>

is a query that retrieves rows from a table.

See	For more information about using the DISTINCT predicate in the SELECT statement, see the SELECT Clause.

Details

You can use the DISTINCT predicate to see whether two values or two row values are equal to one another. The DISTINCT predicate evaluates to true only if all rows that its subquery returns are distinct.

Note: Two null values are not considered distinct.

Example

select count(distinct avghigh) from worldtemps;

select distinct c1.employee, firstname, salary
   from company as c1;

DISTINCT Predicate

Syntax

Form 1:

Form 2:

Arguments

function

expression

SELECT <select-list> FROM <table-expression>

Details

Example

See Also