How do I retrieve data from Firestore using an OR Operator in JavaScript?

I am attempting to read data from a Firestore collection using the following code:

auth.onAuthStateChanged(user => {
if(user) {
  console.log('User logged in:', user)

db.collection('MediCorePatientUsers').where("GPID", "==", user.email)
.get().then((snapshot) => {
    snapshot.docs.forEach(doc => {
        renderPatientList(doc);
        })
    })

document.getElementById("nameOfUser").innerHTML = user.email;

} else {
  console.log('User logged out');
}
});

This works as intended and displays the correct data to my webpage. However, I would like to add another condition to the code, using an 'or' operator to display data where the field "InsuranceCompany" is also equal to the current user email.

db.collection('MediCorePatientUsers').where("GPID", "==", user.email || "InsuranceCompany", "==", user.email)
.get().then((snapshot) => {
snapshot.docs.forEach(doc => {
    renderPatientList(doc);
    })
})

However this is resulting in none of the data displaying when either of the conditions is true. What is incorrect with this code?

With Cloud Firestore, we can combine multiple where() methods to create logical AND queries. These queries are called compound queries in the documentation.

However, as indicated in the documentation (Section “Query Limitations”):

> Cloud Firestore does not support the following types of queries:
>
> - …
> - Logical OR queries. In this case, you should create a separate query for each OR condition and merge the query results in your app.
> - …

In order to implement the solution proposed in the documentation, you can do as follows:

  const usersRef = db.collection('MediCorePatientUsers');

  async function getMediCorePatientUsers(email) {
    const q1 = usersRef.where("GPID", "==", email).get();
    const q2 = usersRef.where("InsuranceCompany", "==", email).get();

    const [querySnapshot1, querySnapshot2] = await Promise.all([q1, q2]);

    const usersArray1 = querySnapshot1.docs;
    const usersArray2 = querySnapshot2.docs;

    return usersArray1.concat(usersArray2);
  }


  //You can then call the asynchronous getMediCorePatientUsers() function as follows
  auth.onAuthStateChanged(user => {
    if(user) {
       getMediCorePatientUsers(user.email).then(result => {
            result.forEach(docSnapshot => {
                renderPatientList(docSnapshot);
            });
       });
    } else {..}
  }

This approach is explained in more detail in the following article, in particular how to do if you need to de-duplicate the two arrays (usersArray1 and usersArray2). (disclaimer, I'm the author of the article)

You can use as follows

> db.collection('MediCorePatientUsers').where("GPID == " + user.email +
> " || InsuranceCompany == " + user.email + "")