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Diffstat (limited to 'guides/source/active_record_querying.textile')
| -rw-r--r-- | guides/source/active_record_querying.textile | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/guides/source/active_record_querying.textile b/guides/source/active_record_querying.textile index 8e23a577e2..8471d67def 100644 --- a/guides/source/active_record_querying.textile +++ b/guides/source/active_record_querying.textile @@ -133,6 +133,24 @@ SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1 <tt>Model.last</tt> returns +nil+ if no matching record is found. No exception will be raised. +h5. +find_by+ + +<tt>Model.find_by</tt> finds the first record matching some conditions. For example: + +<ruby> +Client.find_by first_name: 'Lifo' +# => #<Client id: 1, first_name: "Lifo"> + +Client.find_by first_name: 'Jon' +# => nil +</ruby> + +It is equivalent to writing: + +<ruby> +Client.where(first_name: 'Lifo').first +</ruby> + h5(#first_1). +first!+ <tt>Model.first!</tt> finds the first record. For example: @@ -167,6 +185,24 @@ SELECT * FROM clients ORDER BY clients.id DESC LIMIT 1 <tt>Model.last!</tt> raises +RecordNotFound+ if no matching record is found. +h5(#find_by_1). +find_by!+ + +<tt>Model.find_by!</tt> finds the first record matching some conditions. It raises +RecordNotFound+ if no matching record is found. For example: + +<ruby> +Client.find_by! first_name: 'Lifo' +# => #<Client id: 1, first_name: "Lifo"> + +Client.find_by! first_name: 'Jon' +# => RecordNotFound +</ruby> + +It is equivalent to writing: + +<ruby> +Client.where(first_name: 'Lifo').first! +</ruby> + h4. Retrieving Multiple Objects h5. Using Multiple Primary Keys |