Re: PreparedStatement vs. Statement problem

[Oliver Jowett <oliver(at)opencloud(dot)com>]

yoursoft wrote:
> I have a problem:
> SELECT * FROM mytable WHERE c1 like 'a' UNION ALL SELECT * FROM mytable 
> WHERE c2 like 'a' || '%' AND c2 not like 'a' UNION ALL SELECT * FROM 
> mytable WHERE c2 like '%' || 'a' || '%' AND c2 not like 'a' || '%' AND 
> c2 not like 'a' LIMIT 101 OFFSET 0
>
> Where 'a' is a variable.
> When I run this query from Statement. There is no problem. The result is 
> ordered by: First SELECT, second SELECT third SELECT.
> When I run this query from PreparedStatement ('a' values replaced by ?). 
> The result is ordered by in alphabets.Why?

You don't have an ORDER BY so the result ordering is undefined. The 
planner happens to pick different plans in the two cases which result in 
different orderings.

-O