ZangoDB

Class: Collection

Collection

Class representing a collection.

new Collection()

collection.js, line 10
Note: Do not instantiate directly.

Members

namestring

The name of the collection.

Methods

aggregate(pipeline){Cursor}

collection.js, line 88
Evaluate an aggregation framework pipeline.
Name Type Description
pipeline Array.<object> The pipeline.
Returns:
Type Description
Cursor
Example
col.aggregate([
    { $match: { x: { $lt: 8 } } },
    { $group: { _id: '$x', array: { $push: '$y' } } },
    { $unwind: '$array' }
]);

find(expr, projection_spec){Cursor}

collection.js, line 37
Open a cursor that satisfies the specified query criteria.
Name Type Description
expr object optional The query document to filter by.
projection_spec object optional Specification for projection.
Returns:
Type Description
Cursor
Example
col.find({ x: 4, g: { $lt: 10 } }, { k: 0 });

findOne(expr, projection_spec, cb){Promise}

collection.js, line 57
Retrieve one document that satisfies the specified query criteria.
Name Type Description
expr object optional The query document to filter by.
projection_spec object optional Specification for projection.
cb function optional The result callback.
Returns:
Type Description
Promise
Example
col.findOne({ x: 4, g: { $lt: 10 } }, { k: 0 });

insert(docs, cb){Promise}

collection.js, line 123
Name Type Description
docs object | Array.<object> Documents to insert.
cb function optional The result callback.
Returns:
Type Description
Promise
Examples
col.insert([{ x: 4 }, { k: 8 }], (error) => {
    if (error) { throw error; }
});
col.insert({ x: 4 }, (error) => {
    if (error) { throw error; }
});

remove(expr, cb){Promise}

collection.js, line 215
Delete documents that match a filter.
Name Type Description
expr object The query document to filter by.
cb function optional The result callback.
Returns:
Type Description
Promise
Example
col.remove({ x: { $ne: 10 } }, (error) => {
    if (error) { throw error; }
});

update(expr, spec, cb){Promise}

collection.js, line 198
Update documents that match a filter.
Name Type Description
expr object The query document to filter by.
spec object Specification for updating.
cb function optional The result callback.
Returns:
Type Description
Promise
Example
col.update({
    age: { $gte: 18 }
}, {
    adult: true
}, (error) => {
    if (error) { throw error; }
});