I need a product aggregate function.

I would like it to be in MySQL's flavor of SQL (that is, not in C).

How do I do this? What I'm stuck on is creating an aggregate function -- the docs don't seem to mention how this is done.

Examples of desired usage:

mysql> select product(col) as a from `table`;
+------+
| a    |
+------+
|  144 |
+------+
1 row in set (0.00 sec)

mysql> select col, product(col) as a from `table` group by col;
+-----+------+
| col | a    |
+-----+------+
|   6 |   36 |
|   4 |    4 |
+-----+------+
2 rows in set (0.01 sec)

I need an aggregate function that MySQL doesn't provide.

I would like it to be in MySQL's flavor of SQL (that is, not in C).

How do I do this? What I'm stuck on is creating an aggregate function -- the docs don't seem to mention how this is done.

Examples of desired usage of a product function:

mysql> select product(col) as a from `table`;
+------+
| a    |
+------+
|  144 |
+------+
1 row in set (0.00 sec)

mysql> select col, product(col) as a from `table` group by col;
+-----+------+
| col | a    |
+-----+------+
|   6 |   36 |
|   4 |    4 |
+-----+------+
2 rows in set (0.01 sec)

I need a product aggregate function.

I would like it to be in MySQL's flavor of SQL (that is, not in C).

How do I do this? What I'm stuck on is creating an aggregate function -- the docs don't seem to mention how this is done.

I need a product aggregate function.

I would like it to be in MySQL's flavor of SQL (that is, not in C).

How do I do this? What I'm stuck on is creating an aggregate function -- the docs don't seem to mention how this is done.

Examples of desired usage:

mysql> select product(col) as a from `table`;
+------+
| a    |
+------+
|  144 |
+------+
1 row in set (0.00 sec)

mysql> select col, product(col) as a from `table` group by col;
+-----+------+
| col | a    |
+-----+------+
|   6 |   36 |
|   4 |    4 |
+-----+------+
2 rows in set (0.01 sec)