On Dec 5, 2006, at 2:40 PM, Ruslan Zakirov wrote:
On 12/5/06, Jesse Vincent <[EMAIL PROTECTED]> wrote:
On Tue, Dec 05, 2006 at 04:01:04PM +0800, Agent Zhang wrote:
> Hi,
>
> The Jifty::Manual::Models document contains the following snippet:
>
> # combining restrictions with "AND"
> # note that "AND" is implicit here
> $collection->limit(column=>'col1', value=>'...');
> $collection->limit(column=>'col2', value=>'...');
>
> While testing my Qooqle app in Jifty, however, I found "OR" is
> implicit here instead. By further examining the source of
> Jifty::DBI::Collection, I've seen the following lines:
Here's the way it works:
* Toplevel clauses default to AND
* Subclauses default to OR (though at one point, they defaulted to
whatever made sense. You can make decent guesses about what the
user
means...except that you're often wrong);
* By default, each column gets its own subclauses.
So:
$collection->limit(column => 'col1', value => 'x');
$collection->limit(column => 'col1', value => 'y');
Will generate :
WHERE ( col1 = 'x' OR col2 = 'y');
WHERE ( col1 = 'x' AND col2 = 'y');
How so? My reading of sub limit says this:
sub limit {
my $self = shift;
my %args = (
...
entry_aggregator => 'or',
...
@_ # get the real argumentlist
);
$collection->limit(column => 'col1', value => 'x');
$collection->limit(column => 'col2', value => 'y');
Will generate:
WHERE ( col1 = 'x' ) AND ( col2 = 'y');
$collection->limit(column => 'col1', value => 'x');
$collection->limit(column => 'col2', value => 'x');
$collection->limit(column => 'col2', value => 'y');
Will generate:
WHERE ( col1 = 'x' ) AND ( col2 = 'x' OR col2 = 'y');
You can get tricky by playing with the entry aggregator yourself:
$collection->limit(column => 'col1', value => 'x');
$collection->limit(column => 'col2', value => 'x',
entry_aggregator => 'AND');
$collection->limit(column => 'col2', value => 'y',
entry_aggregator => 'AND');
Will generate:
WHERE ( col1 = 'x' ) AND ( col2 = 'x' OR col2 = 'y');
WHERE ( col1 = 'x' ) AND ( col2 = 'x' AND col2 = 'y');
Thanks. Nice catch.
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