How to Run $unionWith with an Atlas Search $search Query
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Starting in v6.0, the MongoDB $unionWith aggregation stage
supports $search inside the $unionWith
pipeline option. Using $unionWith, you can combine
$search results from multiple collections in the same
database in the result set.
This tutorial demonstrates how to run a $unionWith query
with $search against the companies and inspections
collections in the sample_training database. It takes you through
the following steps:
Set up an Atlas Search index with dynamic mappings for the
companiesandinspectionscollections in thesample_trainingdatabase.Run
$unionWithquery with$searchto perform a union of companies withmobilein their name from thecompaniescollection with companies with same or similar business name in theinspectionscollection.
Before you begin, ensure that your Atlas cluster meets the requirements described in the Prerequisites.
Note
To run a $unionWith query with $search, your
cluster must run MongoDB v6.0 or higher.
Required Access
To create an Atlas Search index, you must have Project Data Access Admin or higher access to the project.
Create the Atlas Search Indexes
In this section, you will create an Atlas Search index named default on
all the fields in the companies collection in the
sample_training database. You will create another Atlas Search index
named default on all the fields in the inspections
collection in the sample_training database. You must perform the
following steps for each collection.
Navigate to the Atlas Search page for your project.
If it isn't already displayed, select the organization that contains your desired project from the Organizations menu in the navigation bar.
If it isn't already displayed, select your desired project from the Projects menu in the navigation bar.
Click your cluster's name.
Click the Search tab.
Create an index.
For your first index, click Create Search Index.
For subsequent indexes, click Create Index.
Select a Configuration Method and click Next.
For a guided experience, select Visual Editor.
To edit the raw index definition, select JSON Editor.
Enter the Index Name, and set the Database and Collection.
In the Index Name field, enter
default.Note
If you name your index
default, you don't need to specify anindexparameter when using the $search pipeline stage. Otherwise, you must specify the index name using theindexparameter.In the Database and Collection section, find the
sample_trainingdatabase, and select the collection.To create an index for the
companiescollection, selectcompanies.To create an index for the
inspectionscollection, selectinspections.
Specify an index definition.
The following index definition dynamically indexes the fields of supported types in the collection. You can use the Visual Editor or the JSON Editor in the Atlas user interface to create the index.
Click Create Search Index.
Close the You're All Set! Modal Window.
A modal window displays to let you know your index is building. Click the Close button.
Wait for the index to finish building.
The index should take about one minute to build. While it is
building, the Status column reads Build in
Progress. When it is finished building, the
Status column reads Active.
Run $unionWith with $search to Search the Collections
➤ Use the Select your language drop-down menu to set the language of the example in this section.
In this section, you will connect to your Atlas cluster and run
the sample query against the indexed collections in the
sample_training database.