mongodb - MongoDB insert field to existing document if does not already exist

Question

I have a document like this (this is very simplified):

{
    'name' : 'test',
    'age' : 16
}

and also this

{
    'name' : 'test2'
}

I want to set all 'age' to 14 if it does not exist.

How can I do this?

Answer 1

试试$exists 运营商：

$this->mongolib->update('people', array('age' => array('$exists' => false)), array('$set' => array('age' => 14)), array('upsert' => true, 'multiple' => true));

Answer 2

我有一个我能想到的迂回方式。我建议您使用正常的更新命令，但只需在您的选择标准中添加一个正则表达式条件，以仅匹配那些没有为“年龄”属性设置值（或数值）的文档。