How do I use a guid in a mongodb shell query

问题:

When using the MongoDB shell, how do I use a guid datatype (which I have used as the _id in my collection).

The following format doesn't work:

>db.person.find({"_id","E3E45566-AFE4-A564-7876-AEFF6745FF"});

Thanks.

回答1:

You have to compare the _id value against an instance of BinData (not against a string). Unfortunately the BinData constructor takes a Base64 string instead of a hex string.

Your GUID value is missing two hex digits at the end, so for the purposes of this example I will assume they are "00". The following values are equivalent:

hex: "E3E45566-AFE4-A564-7876-AEFF6745FF00" (ignoring dashes)

base64: "ZlXk4+SvZKV4dq7/Z0X/AA=="

So your query should be:

>db.person.find({_id : new BinData(3, "ZlXk4+SvZKV4dq7/Z0X/AA==")})

I am assuming that the binary subtype was correctly set to 3. If not, what driver was used to create the data?

回答2:

You can use easily:

.find({ "_id" : CSUUID("E3E45566-AFE4-A564-7876-AEFF6745FF")})

回答3:

You could use the following js function in front of your query like so:

function LUUID(uuid) {
    var hex = uuid.replace(/[{}-]/g, ""); // removes extra characters
    return new UUID(hex); //creates new UUID
}

db.person.find({"_id" : LUUID("E3E45566-AFE4-A564-7876-AEFF6745FF"});

You could save the function in .js file and load it or open it before you make your query and if you copy the value from your results you should rename the function with:

• LUUID for Legacy UUID
• JUUID for Java encoding
• NUUID for .net encoding
• CSUUID for c# encoding
• PYUUID for python encoding