Martin Mueller schrieb am 04.12.2018 um 21:57:
I didn't formulate my question properly, because the query went like
"select alldefects /wordcount"
where alldefects and wordcount are integers.
But none of the different ways of putting the double colon seemed to
work.
One way is to make one of the integers a decimal by multiplying with 1.0
select alldefects * 1.0 / wordcount
The Postgres notation of this simple procedure is very unintuitive. I
haven't been able to remember several times, and most people think of
me as a person with a reasonably good memory.
Postgres supports the SQL standard's CAST operator:
select cast(alldefects as decimal) / wordcount
The "Postgres way" would be:
select alldefects::decimal / wordcount
There is no obvious place in the documentation to look this up.
This is covered in the chapter "Type Casts"
https://www.postgresql.org/docs/current/sql-expressions.html#SQL-SYNTAX-TYPE-CASTS
