Selecting Aggregates from Procedures
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In addition to selecting values from a procedure, you can use aggregate functions. For example, to use ORG_CHART to display a count of the number of departments, use the following statement:
SELECT COUNT(DEPARTMENT) FROM ORG_CHART;
The results are:
COUNT ============ 24
Similarly, to use ORG_CHART to display the maximum and average number of employees in each department, use the following statement:
SELECT MAX(EMP_CNT), AVG(EMP_CNT) FROM ORG_CHART;
The results are:
MAX AVG ======= ======= 5 2
If a procedure encounters an error or exception, the aggregate functions do not return the correct values, since the procedure terminates before all rows are processed.