mysql> select sum(x) from (select 1 as x) as temp;
+--------+
| sum(x) |
+--------+
| 1 |
+--------+
1 row in set (0.00 sec)

mysql> select sum(x) from (select 1 as x limit 0) as temp;
+--------+
| sum(x) |
+--------+
| NULL |
+--------+
1 row in set (0.00 sec)

mysql> select sum(0+x) from (select 1 as x limit 0) as temp;
+----------+
| sum(0+x) |
+----------+
| NULL |
+----------+
1 row in set (0.00 sec)

mysql> select 0+sum(x) from (select 1 as x limit 0) as temp;
+----------+
| 0+sum(x) |
+----------+
| NULL |
+----------+
1 row in set (0.00 sec)

> What happens if you deploy the cheap, self-obvious fix that's fitted to the other's idiocy, rather than trying to forever and no matter what speak your own mental language to everyone ?

A happy ending I'd imagine, if at the cost of having to study the other's idiocy in depth for the cheap fix to become obvious. Which strikes me as something you work at quite a bit.

The link calls to mind the fox and the stork. Though now I wanna know what the hedgehog did!!

Not that I can reproduce the item on mysql's notion of sql,

mysql> select sum("");
+---------+
| sum("") |
+---------+
| 0 |
+---------+
1 row in set (0.00 sec)

mysql> select sum(0);
+--------+
| sum(0) |
+--------+
| 0 |
+--------+
1 row in set (0.00 sec)

mysql> select sum("1");
+----------+
| sum("1") |
+----------+
| 1 |
+----------+
1 row in set (0.00 sec)

mysql> select sum("q");
+----------+
| sum("q") |
+----------+
| 0 |
+----------+
1 row in set, 1 warning (0.00 sec)

But... what happens if you type out your sum as SUM(0+...) rather than SUM(...) ?

I don't merely ask because I am trying to provide the immediate solution ; and I certainly do not ask in that exact form because I am merely trying to provide the immediate solution.

What happens if you deploy the cheap, self-obvious fix that's fitted to the other's idiocy, rather than trying to forever and no matter what speak your own mental language to everyone ?