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mongodbgrailsgrails-orm

Why is GORM returning a nested array for my list property?

I have the following domain objects:

class Foo {
 List<Bar> bars

 static hasMany = [bars: Bars]
 static mapWith = 'mongo'
}

class Bar {
 Foo foo

 static belongsTo = [foo: Foo]
 static mapWith = 'mongo'
}

The following code in a service:

Bar bar1 = new Bar('bar1')
Bar bar2 = new Bar('bar2')
Bar bar3 = new Bar('bar3')
foo.addToBars(bar1)
foo.addToBars(bar2)
foo.addToBars(bar3)
foo.save

And the following code in a controller:

def foo = Foo.findAll()
def bars = foo.bars

Why is bars a nested array?

I get something like: [['bar1','bar2','bar3']]
I am expecting something like ['bar1','bar2','bar3']

More info:

  • Grails 2.4.3
  • mongodb 3.0.2
  • hibernate 3.6.10.17
Solution

  • The problem was that I was doing .bars on the object returned by findAll. I changed it to findOne() and everything worked as expected.

    Solution:

    def foo = Foo.findOne() // was: def foo = Foo.findAll()
def bars = foo.bars