EZ_Where help, field IS NULL

Rails
1

I am trying to create a conditions caluse with ez_where that looks like:

[“enabled = ? AND age_min <= ? AND (age_max >= ? OR age_max IS NULL)”,
true, range[:max], range[:min]]

Everything is fine except for the last part: “OR age_max IS NULL”

The problem seems to stem that ez_where does not provide a way to use
“IS NULL” and “IS NOT NULL”. Here is what I tried so far:

conditions = Caboose::EZ::Condition.new do
  enabled == true
  age_min <= range[:max]
  any do
    age_max >= range[:min]
    age_max == nil
  end
end

But this leaves that last clause out resulting in:
“enabled = ? AND age_min <= ? AND (age_max >= ?)”

I had some minor luck with using append inside the any block:

any do
age_max >= range[:min]
append ‘age_max IS NULL’
end

however this generates the appended clause with an AND instead of an OR.

Any tips?

2

Hi Alex-

On Oct 11, 2006, at 12:14 PM, Alex W. wrote:

The problem seems to stem that ez_where does not provide a way to use

however this generates the appended clause with an AND instead of
an OR.

Any tips?

You can't just use nil on the right hand side of an ez_where

expression because it will leave out that expression as you
discovered. This is so you don’t have to say

foo == params[:bar] if params[:bar]

you can leave off the if part and if params[:bar] is nil that
statement will be left out of the query. This makes complex queried
way easier to write. But it also makes IS NULL a special case so
there is a special syntax for that:

 conditions = EZ::Where::Condition.new do
   enabled == true
   age_min <= range[:max]
   any do
     age_max >= range[:min]
     age_max == :null
   end
 end

Also it looks like you are using an old version, please update to the
latest here:

svn checkout svn://rubyforge.org/var/svn/ez-where

So for now the way to do IS NULL and IS NOT NULL is liek this:

IS NULL

foo == :null

IS NOT NULL

foo! == :null

or append like you used.

-Ezra

3

Ezra Z. wrote:

you can leave off the if part and if params[:bar] is nil that
statement will be left out of the query. This makes complex queried
way easier to write. But it also makes IS NULL a special case so
there is a special syntax for that:

 conditions = EZ::Where::Condition.new do
   enabled == true
   age_min <= range[:max]
   any do
     age_max >= range[:min]
     age_max == :null
   end
 end

Also it looks like you are using an old version, please update to the
latest here:

svn checkout svn://rubyforge.org/var/svn/ez-where

Ah, I was linked to a non rubyforge svn somehow. Patched up and using
:null and all is well.

Thanks for the awesome plugin, Ezra.