Query and projection operators

You can refine your queries with the MongoDB query and projection operators. For example, in the mongo shell, to find members of the cartype collection with an age greater than 10, you can use the $gt operator: db.cartype.find({"age":{"$gt":10.0}}).

The JSON wire listener supports the skip, limit, and sort query options. You can set these options by using the mongo shell or MongoDB drivers.

• Query selectors
• Projection operators

Query selectors

Array query operators

Table 1. Array query operators

MongoDB command	JSON collections	Relational tables	Details
$elemMatch	Yes	No
$size	Yes	No

Comparison query operators

Table 2. Comparison query operators

MongoDB command	JSON collections	Relational tables	Details
$all	Yes	Yes	Supported for primitive values and simple queries only. The operator is only supported when it is the only condition in the query document.
$eq	Yes	Yes
$gt	Yes	Yes
$gte	Yes	Yes
$in	Yes	Yes
$lt	Yes	Yes
$lte	Yes	Yes
$ne	Yes	Yes
$nin	Yes	Yes
$query	Yes	Yes

Element query operators

Table 3. Element query operators

MongoDB command	JSON collections	Relational tables	Details
$exists	Yes	No
$type	Yes	No

Evaluation

Table 4. Evaluation query operators

MongoDB command	JSON collections	Relational tables	Details
$mod	Yes	Yes
$regex	Yes	Yes	The only supported value for the $options flag is i, which specifies a case-insensitive search.
$text	Yes	Yes	The $text query operator support is based on MongoDB version 2.6. You can customize your text index and take advantage of additional text query options by creating a basic text search index with the createTextIndex command. For more information, see HCL OneDB JSON commands.
$where	No	No

Geospatial query operators

Geospatial queries are supported by using the GeoJSON format. The legacy coordinate pairs are not supported.

Table 5. Geospatial query operators

MongoDB command	JSON collections	Relational tables	Details
$geoWithin	Yes	No
$geoIntersects	Yes	No
$near	Yes	No
$nearSphere	Yes	No

JavaScript™ query operators

The JavaScript query operators are not supported.

Logical query operators

Table 6. Logical query operators

MongoDB command	JSON collections	Relational tables	Details
$and	Yes	Yes
$or	Yes	Yes
$not	Yes	Yes
$nor	Yes	Yes

Projection operators

Projection operators

Table 7. Projection operators

MongoDB command	JSON collections	Relational tables	Details
$	No	No
$elemMatch	Yes	No
$meta	Yes	Yes
$slice	No	No

Query modifiers

Table 8. Query modifiers

MongoDB command	JSON collections	Relational tables	Details
$comment	No	No
$explain	Yes	Yes
$hint	Yes	No
$orderby	Yes	Yes

For more information about the MongoDB features, see http://docs.mongodb.org/manual/reference/.