COUNT

Returns the number of rows returned by the query.

Syntax

See Oracle Database SQL Language Reference.

Restrictions

The following restrictions apply when you use the COUNT function in the SELECT command:

• The expression must be a column, a numeric constant, or a string constant.

• The function does not support the DISTINCT or ALL keywords.

• The function does not support the OVER clause.

• The function always counts all rows for the query, including duplicates and nulls.

Examples

This example returns the number of incidents for which flood_controlled is 0 (zero):

select count(*) from incident where flood_controlled = 0;

This example returns the number of problems for which problem_key includes ORA-600:

select count(*) from problem where problem_key like '%ORA-600%';