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Improve ar associations habtm docs a bit

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Carlos Antonio da Silva 2012-01-31 09:40:38 -02:00
parent f457f87241
commit 0d5f7dac3d
1 changed files with 2 additions and 5 deletions
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7
railties/guides/source/association_basics.textile
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@ -1545,12 +1545,9 @@ h6(#has_and_belongs_to_many-collection-find). <tt><em>collection</em>.find(...)<
The <tt><em>collection</em>.find</tt> method finds objects within the collection. It uses the same syntax and options as +ActiveRecord::Base.find+. It also adds the additional condition that the object must be in the collection.
<ruby>
@new_assemblies = @part.assemblies.all(
:conditions => ["created_at > ?", 2.days.ago])
@assembly = @part.assemblies.find(1)
</ruby>
NOTE: Beginning with Rails 3, supplying options to the +ActiveRecord::Base.find+ method is discouraged. Use <tt><em>collection</em>.where</tt> instead when you need to pass conditions.
h6(#has_and_belongs_to_many-collection-where). <tt><em>collection</em>.where(...)</tt>
The <tt><em>collection</em>.where</tt> method finds objects within the collection based on the conditions supplied but the objects are loaded lazily meaning that the database is queried only when the object(s) are accessed. It also adds the additional condition that the object must be in the collection.
@ -1669,7 +1666,7 @@ h6(#has_and_belongs_to_many-counter_sql). +:counter_sql+
Normally Rails automatically generates the proper SQL to count the association members. With the +:counter_sql+ option, you can specify a complete SQL statement to count them yourself.
NOTE: If you specify +:finder_sql+ but not +:counter_sql+, then the counter SQL will be generated by substituting +SELECT COUNT(*) FROM+ for the +SELECT ... FROM+ clause of your +:finder_sql+ statement.
NOTE: If you specify +:finder_sql+ but not +:counter_sql+, then the counter SQL will be generated by substituting the +SELECT ... FROM+ clause of your +:finder_sql+ statement by +SELECT COUNT(*) FROM+.
h6(#has_and_belongs_to_many-delete_sql). +:delete_sql+