Casting NULL type when updating multiple rows

Question

I have a problem when I try to update many rows at the same time.

Here is the table and query I use (simplified for better reading):

table<

Answer 1

Your script will create a temporary table from foo. It will have the same data types as foo. Use an impossible condition so it is empty:

select x, y, pkid
into temp t
from foo
where pkid = -1

Make your script to insert into it:

insert into t (x, y, pkid) values
(null, 20, 1),
(null, 50, 2)

Now update from it:

update foo 
set x=t.x, y=t.y 
from t
where foo.pkid=t.pkid

Finally drop it:

drop table t