使用正则表达式在MongoDB中搜索任何值？

Question

I'm very new to MongoDB and regex so please bear with me. The MongoDB documentation has an example for searching with regular expressions:

http://docs.mongodb.org/manual/reference/operators/#_S_regex

However, it only shows how to search the values of predetermined keys. I'm unsure how to write a query to search all values in a collection, if anyone can point it out that would be great.

Answer 1

If you didn't care about size of DB (or performance), you could potentially use a mapReduce function to de-normalize the data into a structure which is more easily searched. But, this will significantly increase the size of the DB as you'll duplicate all data for the collection.

Pseudo-code:

// recursive
// building a full property path
for(var key in obj) {
    emit(this._id, { orig: obj[key], src: path + "." + key });
    // recursive call emitChildren(path, key)
}

Depending on the complexity of the data, it could be reasonable.

Or, you might be able to use $where to do a regex on each key/value of all documents (as you can execute arbitrary JavaScript when using $where).

No option is going to perform well (even a built in option) nor play to the strengths of mongoDB if you're running a regular expression on every value in every document in a collection.