In general, aggregation is a consideration of a collection of objects that are bound together as a single entity. SQL provides a set of aggregate functions that perform operations on all the entities of the column of a table considering them as a single unit. Following are the SQL aggregate functions −
| Sr.No. | Function & Description |
|---|---|
| 1 | APPROX_COUNT_DISTINCT() Returns the approximate number of rows with distinct expression values. |
| 2 | AVG() Returns the average of the fields in a particular column that has only numeric values. |
| 3 | CHECKSUM_AGG() Returns the checksum value. |
| 4 | COUNT_BIG() Returns the count of the number of items or rows selected by the select statement. |
| 5 | COUNT() Returns the number of non-NULL values in a particular column. |
| 6 | GROUPING() Returns whether the specified column expression in a group by list is aggregate or not. |
| 7 | GROUPING_ID() Returns the level of grouping. |
| 8 | MAX() Returns the maximum value among the fields in a particular column. |
| 9 | MIN() Returns the minimum value among the fields in a particular column. |
| 10 | STDEV() Returns the statistical standard deviation of the fields (numerical values) in a particular column. |
| 11 | STDEVP() Returns the population standard deviation for the fields (numerical values) in a particular column. |
| 12 | SUM() Returns the sum of all the fields (numeric) in a particular column. |
| 13 | VAR() Returns the statistical standard variance of the fields (numerical values) in a particular column. |
| 14 | VARP() Returns the population standard variance of the fields (numerical values) in a particular column. |