Rails ActiveRecord Multiple WHERE Statements

Question

I have an array that contains some conditions, say: ages = [1, 4, 10].

I am trying to build a query where it will return the ages in the array. The array can be of arbitrary length. So something like:

Person.where("age == :ages", {:ages => ages})

Now this obviously does not work as :ages would be an array, when according to the equality statement above, it's expecting a string.

I'm trying to have it achieve something along the lines of: WHERE age = 1 AND age = 4 AND age = 10 according to the ages array.

All examples online discuss how to use multiple where conditions when they are separate variables, in which case is easy as you would do: Person.where("condition1 = :first AND condition2 = :second....). I have unknown number of items in the array and I want to filter all my query result by them.

You should accept one of the answers if it fits your questions — MrYoshiji
– MrYoshiji, Commented Jan 29, 2013 at 22:16

MrYoshiji · Accepted Answer · 2013-01-29 21:35:01Z

2

It is already supported by ActiveRecord and the where statement:

ages = [1, 5, 12]
Person.where(age: ages)
# This will generates a query like:
# SELECT * FROM persons WHERE age IN(1, 5 ,12)

This way of querying is also better than 'hard-coding' condition (passing strings to the where statement). By using Hash parameters you let ActiveRecord deal with all the DB-Query translation work.

answered Jan 29, 2013 at 21:35

MrYoshiji

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3 Comments

darksky Over a year ago

I was doing it as Person.where(age => ages) which is apparently incorrect. Could you explain the colon syntax? And what the hash form of where means please?

deefour Over a year ago

The colon is Ruby 1.9 optional syntax for a Hash. { :age => ages } and { age: ages } are functionally identical.

MrYoshiji Over a year ago

Except that you cant assign a string in the new Ruby 1.9 Hash Syntax: { 'foo' => 'bar' } works when { 'foo': 'bar' } does not.

deefour · Accepted Answer · 2013-01-29 21:34:40Z

2

I think you're looking for an IN query since age cannot be both 1 and 4 and 10 for some single column integer value.

Person.where(age: ages)

answered Jan 29, 2013 at 21:34

deefour

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1 Comment

MrYoshiji Over a year ago

Nothing to do here but someone stole your profile picture on StackOverflow!

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