Does the GraphQL query operator return substrings?

Retired Boards Appdev Custom Storefronts
1

I am using the following query

query LocationsByExternalID{
     companyLocations(first: 20, query: "external_id:=${externalId}") {
         edges {
            node {
              id
              name
            }
         }
      }
}

External IDs are supposed to be distinct, but this query sometimes returns multiple edges!

I noticed that this will match any substring of externalId: e.g. externalId:400 returns ids of 400 and 1400

Is there another operator for strict equality? I can not find it.