PostgreSQL provides a wide range of aggregate functions to perform calculations on groups of values rather than individual values returned by a SELECT statement. The available aggregate functions in PostgreSQL include:
1. AVG(): This function returns the average of a set of values.
Example usage:
SELECT AVG(price) FROM products;2. SUM(): This function returns the sum of a set of values.
Example usage:
SELECT SUM(quantity) FROM orders;3. MIN(): This function returns the minimum value of a set of values.
Example usage:
SELECT MIN(price) FROM products;4. MAX(): This function returns the maximum value of a set of values.
Example usage:
SELECT MAX(price) FROM products;5. COUNT(): This function returns the number of rows or non-null values in the specified column.
Example usage:
SELECT COUNT(*) FROM users;6. BIT_AND(): This function returns the bitwise AND of all input values.
Example usage:
SELECT BIT_AND(value) FROM my_table;7. BIT_OR(): This function returns the bitwise OR of all input values.
Example usage:
SELECT BIT_OR(value) FROM my_table;8. BOOL_AND(): This function returns true if all input values are true, and false otherwise.
Example usage:
SELECT BOOL_AND(is_active) FROM users;9. BOOL_OR(): This function returns true if at least one input value is true, and false otherwise.
Example usage:
SELECT BOOL_OR(is_active) FROM users;10. ARRAY_AGG(): This function returns an array of values for a given column.
Example usage:
SELECT ARRAY_AGG(price) FROM products;These are just a few of the aggregate functions provided by PostgreSQL. Each function performs a specific calculation on a set of values, making it easier to retrieve the desired information from your database.