Mongoexport错误解析查询

Question

Im trying to do a mongoexport to CSV but only selecting certain records with a query. Here's my command (windows 7 cmd):

mongoexport --host foo.com --port 27017 --username bar -p --db foo --csv --fields col1,col2,col3 --collection bar --out dump_q.csv --query '{"recent":"yes"}'

However after entering the password, I get an error:

assertion: 16619 code FailedToParse: FailedToParse: Expecting '{': offset:0

The command works fine without the query argument but I cant figure out whats wrong with the query:

--query '{"recent":"yes"}'

Any help much appreciated

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Summary of answer:

1. Make sure you use double quotes on enclose the query and single quotes to enclose strings eg

   --query "{'recent':'yes'}"

2. Also make sure you don't have a space in your query otherwise the command prompt will parse it as another argument. So don't have :

   --query "{'recent': 'yes'}" (notice the space in-between)

3. Queries which include nested fields don't work such as:

   --query "{'folder.recent':'yes'}"

Answer 1

You'll need to use double quotes to contain the query string (and either single quotes or two quotes to escape inside of the string)

--query "{'recent':'yes'}"

Complete:

mongoexport --host foo.com --port 27017 --username bar -p
        --db foo --csv --fields col1,col2,col3 
        --collection bar --out dump_q.csv --query "{'recent':'yes'}"

Answer 2

From mongoexport documentation :

--query , -q

 Provides a JSON document as a query that optionally limits the documents returned in the export. 

Your query string seems to be correctly formated. You can even ommit the double quotes around recent .

Single or double quotes don't seem to matter, as long as you are persistent in using different types on the outside and the inside.

Are you sure this is a valid query though? What is the output if you run the following in the database? What about a find() ?

db.bar.count({"recent":"yes"})