CODEWITHSUNDEEP
stringmongodbvariables
Raja
Raja

Reputation: 442

MongoDb Variable to String

In MongoDb Shell

db.keyword.update({"state":"UT"}, {$unset:{'abc.def':1}});

unsets removes def from abc . However, if I do it like this :

var key = 'def'

var key1 = 'abc.'+key 
db.keyword.update({"state":"UT"}, {$unset:{key1:1}});

doesnt unset def.

How do I get to unset "abc.def" by passing key1 ?

Upvotes: 2

Views: 1625

Answers (1)

Sergio Tulentsev
Sergio Tulentsev

Reputation: 230461

Yes, this is how json parser works. By the standard, hash keys must be enclosed in quotes, but some parsers are too forgiving and allow you to omit them. So, this is how mongo sees your code.

db.keyword.update({"state": "UT"}, {"$unset": {"key1": 1}});

You can get around this problem by constructing the hash manually. Something like this:

var key = 'def';
var key1 = 'abc.' + key;

var mod = {"$unset": {}};
mod["$unset"][key1] = 1;

db.keyword.update({"state": "UT"}, mod);

Upvotes: 5

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