The SQLite json_group_object() function is an aggregate function that returns a JSON object comprised of all name/value pairs in the aggregation.
In other words, it constructs a JSON object from the values provided by its arguments.
Continue readingThe SQLite json_group_array() function is an aggregate function that returns a JSON array comprised of all values in the aggregation.
In other words, it constructs an array from the values provided by its argument.
Continue readingMost of the major RDBMSs have a function that enables us to return our query results as a comma separated list.
That is, we can use such a function to convert each row into a separate list item, within a comma separated list.
Below are examples of how to achieve this in some of the more popular RDBMSs.
Continue readingIn MariaDB, we can use the GROUP_CONCAT() function to return our query results as a comma separated list. By that I mean, for a given column, we can convert all rows into a single row that contains a comma separated list of the values that made up that column. Each row is a separate item in the list.
In PostgreSQL, the SUM() function computes the sum of the non-null input values and returns the result.
In other words, it adds numbers and returns the result.
Continue readingIn PostgreSQL, the AVG() function computes the average (arithmetic mean) of all the non-null input values, and returns the result.
In PostgreSQL, the MAX() function computes the maximum of the non-null input values and returns the result.
This function can be used on any numeric, string, date/time, or enum type, as well as inet, interval, money, oid, pg_lsn, tid, and arrays of any of these types.
In PostgreSQL, the MIN() function computes the minimum of the non-null input values and returns the result.
This function can be used on any numeric, string, date/time, or enum type, as well as inet, interval, money, oid, pg_lsn, tid, and arrays of any of these types.
In MySQL, the SUM() aggregate function returns the sum of a given expression.
It can also be used to return the sum of all distinct (unique) values in an expression.
Continue readingIn Oracle, we can use the LISTAGG() function to convert our query results to a comma separated list.
So, instead of each value being output in a separate row, all values are output in a single row, separated by a comma (or some other delimiter of our choosing).
Continue reading