Can someone explain how this writable CTE works? Or does it not?
What I tried to do was to make those non-null/non-empty values of
suppliers.suppliercode unique by (1) nullifying any blank, but non-null,
suppliercode, then (2) appending the supplierid values to the suppliercode
values for tho
Hi Victor,
> I see 2 problems with this query:
> 1) CTE is just a named subquery, in your query I see no reference to
> the “upd_code” CTE.
>Therefore it is never gets called;
So, in conclusion, my misconception about CTE in general was that all CTE get
called without being referenced.
Tha
> I think this explanation is wrong --- if you run the query with EXPLAIN
> ANALYZE, you can see from the rowcounts that the writable CTE *does* get
> run to completion, as indeed is stated to be the behavior in the fine
> manual.
>
> However, for a case like this where the main query isn't readi
I am troubled to find out that a SELECT statement produces fewer rows than the
actual row count and have not been able to answer myself as to why. I hope
someone could help shedding some light to this.
I attempted to generate a set of INSERT statements, using a the following
SELECT statement,
This seems to answer my question. I completely forgot about the behavior of
NULL value in the text concatenation.
http://www.postgresql.org/docs/9.1/static/plpgsql-statements.html#PLPGSQL-QUOTE-LITERAL-EXAMPLE
Because quote_literal is labelled STRICT, it
will always return null when calle
