For instance, look at my database structure:
I want to run a query similar to this:
db.collection('identites').where("partyMembers", "array-contains", {name: "John Travolta"})
Thanks.
As Frank has explained in his answer it is not possible, with array-contains, to query for a specific property of an object stored in an array.
However, there is a possible workaround: it is actually possible to query for the entire object , as follows, in your case:
db.collection('identites').where("partyMembers", "array-contains", {id: "7LNK....", name: "John Travolta"})
Maybe this approach will suit your needs (or maybe not....).
The array-contains
operations checks if an array, contains a specific (complete) value. It can't check if an array of objects, contains an item with a specific value for a property.
The only way to do your query, is to add an additional field to your document with just the value you want to query existence on. So for example: partyMemberNames: ["John Travolta", "Olivia Newton"]
.
If you want to extract name: "John Travolta" from "partyMembers" array in a document. you can achieve this by some similar approach in which you can loop through all arrays in a document to find this name.
const [names, setNames] = React.useState([]) const readAllNames = async() => { const snapshot = await firebase.firestore().collection('identites').doc(documentID).get() const filterData = snapshot.data().question.map(val => val.name === "John Travolta" ? val : null) setNames( filterData.filter(e=>e) ); }
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