- Build Charts >
- Filter Documents in the Visualization
Filter Documents in the Visualization¶
To display a subset of results in your data that match a given criteria, use the Filters input bar above the chart display. Input a filter document employing the same syntax used in the query portion of the db.collection.find() method. After entering a filter document, click Apply to see the filter reflected in your visualization.
Note
Filters on large collections may have performance issues if there are not appropriate indexes on the collection.
Basic Filter Example¶
The following chart shows the average runtime of movies by genre.
The filter of {runtime: {$gte: 120 }} means that we are only
taking into account movies which have a runtime greater than or
equal to 120 minutes.
Regular Expression (RegEx) Filter¶
RegEx filters allow you to apply a regular expression as the match criteria to restrict the data MongoDB Charts displays. The expression uses the following syntax:
The $options are optional and are the same as the
$regex options in the MongoDB shell.
Example
Filter data to document fields that start with a specific letter
To find all documents where the jobs field begins with the
letter A, you would write the following in the
Filter bar:
Filter data to document fields that start with a specific letter ignoring case
To find all documents where the jobs field begins with the
letter A or a, you would write the following in the
Filter bar:
Note
The quotation marks around the regular expression are required. You may not use forward slashes to delineate the regex value as you may in the MongoDB shell.
Relative Date Filter¶
Relative Date Filters allow you to specify a date from which MongoDB Charts restricts the data displayed. For example, you can set a Relative Date Filter to display data from only the last month or last year. To create a filter spanning from the specified date to the current date, specify the number of milliseconds since the Unix epoch of January 1, 1970. Use this date in conjunction with a comparison query operator to set the inclusive or exclusive time range of the data displayed.
Example
The following Relative Date Filter returns documents that have a
timestamp field which resolves to a date less than 30 days from
the current date:
First, the inner new Date() constructor generates the current
date in milliseconds since the Unix epoch of January 1, 1970. The
mathematical series 30 * 24 * 60 * 60 * 1000 results in the
number of milliseconds elapsed in 30 days. The filter takes the
current date in milliseconds since the Unix epoch and subtracts the
number of milliseconds in 30 days. This results in a new millisecond
value which the filter passes to an outer new Date() constructor
and resolves to the date 30 days prior to the time the user executes
the filter.
Using a mathematical series as shown here allows the filter to always span a relative timeframe of 30 days prior to the time the user executes the filter.
For a more complete example of a relative date filter, see the Relative Date Filter Example.
ISO-8601 Dates
The date functions utilized in MongoDB Charts filters are consistent and
compatible with the date functions used in the
mongo shell. As a result, you can also use the
ISODate() constructor in your Charts query filters.
Specifying an ISODate() constructor with no parameters exhibits
the same behavior as specifying a new Date() constructor with no
paramters, both returning the current date in their respective
formats.
Example
The following filter returns documents that have a
timestamp field between January 1, 2017 and December 31, 2017
inclusively:
Relative Date Filter Example¶
The following chart visualizes workout data. Each document in the collection represents an individual workout activity, which contains information such as the type of workout and various exercise statistics. This line chart shows the distance per month covered across all workouts over the past year (365 days):
The chart utilizes the following filter:
This filter returns documents where the Workout Date (As Date)
field is within one year prior to the time Charts executes the
query. The (new Date() - 365 * 24 * 60 * 60 * 1000 ) parameter
results in the date one year prior to the current date as expressed in
milliseconds since the Unix epoch. Charts returns documents
with a value greater than or equal to this date, as signified by the
$gte operator.
Date() is not supported
The Date() function (as opposed to the new Date()
constructor) returns the current date as a string, so it cannot be
used for filtering dates in Charts. Use:
new Date(),ISODate(), ornew ISODate()