CODEWITHSUNDEEP
firebasegoogle-cloud-firestore
Jorn
Jorn

Reputation: 272

Cannot query Firestore database on multiple values

I have a database full with cars. The JSON format is this:

docId: {
        "countries": ["Netherlands"]
        "cities": ["Amsterdam"]
   }

I cannot query both arrays.

db.collection("EU-CARS")
    .whereArrayContains("countries", "Netherlands")
    .whereArrayContains("cities", "Amsterdam");

How to solve this?

Upvotes: 0

Views: 717

Answers (1)

Alex Mamo
Alex Mamo

Reputation: 138969

As you already noticed, Firestore allow you to filter your cars using only one whereArrayContains() method call. If you will use more than one, an error like this will occur:

Caused by: java.lang.IllegalArgumentException: Invalid Query. Queries only support having a single array-contains filter.

There are two ways in which you can solve this. The first one would be to change the structure your car document like this:

docId
  |
  --- filters
       |
       --- "country": "Netherlands"
       |
       --- "city": "Amsterdam"

In this way you can filter your database using:

Query query = db.collection("EU-CARS").
    .whereEqualTo("filters.country", "Netherlands")
    .whereEqualTo("filters.city", "Amsterdam");

Chaining multiple whereEqualTo() methods is permitted in Firestore.

Or if you still want to use arrays, simply concatenate both names into a sigle one:

docId
  |
  --- "countries_cities": ["Netherlands_Amsterdam", "Netherlands_Utrecht"]

The corresponding query should look like this:

db.collection("EU-CARS")
    .whereArrayContains("countries_cities", "Netherlands_Amsterdam");

Edit:

If you have multiple countries/cities, then the structure of your document should look like this:

docId
  |
  --- filters
       |
       --- "Netherlands": true
       |
       --- "Amsterdam": true
       |
       --- "Utrecht": true

In this way you can filter your database using:

Query query = db.collection("EU-CARS").
    .whereEqualTo("filters.Netherlands", true)
    .whereEqualTo("filters.Amsterdam", true);

Upvotes: 1

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