firebase.firestore. Query
A Query
refers to a Query which you can read or listen to. You can also construct refined Query
objects by adding filters and ordering.
Property
firestore
non-null firebase.firestore.Firestore
The Firestore
for the Cloud Firestore database (useful for performing transactions, etc.).
Methods
endAt
endAt(snapshotOrVarArgs) returns firebase.firestore.Query
Creates a new query where the results end at the provided document (inclusive). The end position is relative to the order of the query. The document must contain all of the fields provided in the orderBy
of this query.
Parameter |
|
---|---|
snapshotOrVarArgs |
(non-null firebase.firestore.DocumentSnapshot or repeatable any type) The snapshot of the document the query results should end at or the field values to end this query at, in order of the query's order by. |
- Returns
-
non-null firebase.firestore.Query
The created query.
endBefore
endBefore(snapshotOrVarArgs) returns firebase.firestore.Query
Creates a new query where the results end before the provided document (exclusive). The end position is relative to the order of the query. The document must contain all of the fields provided in the orderBy
of this query.
Parameter |
|
---|---|
snapshotOrVarArgs |
(non-null firebase.firestore.DocumentSnapshot or repeatable any type) The snapshot of the document the query results should end before or the field values to end this query before, in order of the query's order by. |
- Returns
-
non-null firebase.firestore.Query
The created query.
get
get(options) returns firebase.firestore.QuerySnapshot
Executes the query and returns the results as a QuerySnapshot
.
Parameter |
|
---|---|
options |
Optional An options object to configure how the data is retrieved. Value must not be null. |
- Returns
-
non-null firebase.firestore.QuerySnapshot
A promise that will be resolved with the results of the query.
limit
limit(limit) returns firebase.firestore.Query
Creates a new query where the results are limited to the specified number of documents.
Parameter |
|
---|---|
limit |
number The maximum number of items to return. |
- Returns
-
non-null firebase.firestore.Query
The created query.
onSnapshot
onSnapshot(optionsOrObserverOrOnNext, observerOrOnNextOrOnError, onError) returns function()
Attaches a listener for QuerySnapshot
events. You may either pass individual onNext
and onError
callbacks or pass a single observer object with next
and error
callbacks. The
listener can be cancelled by calling the function that is returned when onSnapshot
is called.
NOTE: Although an onCompletion
callback can be provided, it will never be called because the snapshot stream is never-ending.
Parameter |
|
---|---|
optionsOrObserverOrOnNext |
(non-null firebase.firestore.SnapshotListenOptions, non-null Object, or function(non-null firebase.firestore.DocumentSnapshot)) This can be an observer object or an onNext function callback. It can also be an options object containing { includeMetadataChanges: true } to opt into events even when only metadata changed. |
observerOrOnNextOrOnError |
(non-null Object, function(non-null firebase.firestore.DocumentSnapshot), or function(non-null firebase.FirebaseError)) If you provided options, this will be an observer object or your onNext callback. Else, it is an optional onError callback. |
onError |
Optional function(non-null firebase.FirebaseError) If you didn't provide options and didn't use an observer object, this is the optional onError callback. |
- Returns
-
non-null function()
An unsubscribe function that can be called to cancel the snapshot listener.
orderBy
orderBy(fieldPath, directionStr) returns firebase.firestore.Query
Creates a new query where the results are sorted by the specified field, in descendin or ascending order.
Parameter |
|
---|---|
fieldPath |
(string or non-null firebase.firestore.FieldPath) The field to sort by. |
directionStr |
Optional string Optional direction to sort by ( |
- Returns
-
non-null firebase.firestore.Query
The created query.
startAfter
startAfter(snapshotOrVarArgs) returns firebase.firestore.Query
Creates a new query where the results start after the provided document (exclusive). The starting position is relative to the order of the query. The document must contain all of the fields provided in the orderBy
of this query.
Parameter |
|
---|---|
snapshotOrVarArgs |
(non-null firebase.firestore.DocumentSnapshot or repeatable any type) The snapshot of the document to start after or the field values to start this query after, in order of the query's order by. |
- Returns
-
non-null firebase.firestore.Query
The created query.
startAt
startAt(snapshotOrVarArgs) returns firebase.firestore.Query
Creates a new query where the results start at the provided document (inclusive). The starting position is relative to the order of the query. The document must contain all of the fields provided in the orderBy
of the query.
Parameter |
|
---|---|
snapshotOrVarArgs |
(non-null firebase.firestore.DocumentSnapshot or repeatable any type) The snapshot of the document you want the query to start at or the field values to start this query at, in order of the query's order by. |
- Returns
-
non-null firebase.firestore.Query
The created query.
where
where(fieldPath, opStr, value) returns firebase.firestore.Query
Creates a new query that returns only documents that include the specified fields and where the values satisfy the constraints provided.
Parameter |
|
---|---|
fieldPath |
(string or non-null firebase.firestore.FieldPath) The path to compare. |
opStr |
string The operation string. The operators "<", "<=", "==", ">", and ">=" can be used to compare a field to a specified value. The operator "array-contains" can be used to find documents where a field is an array and contains a specified value. |
value |
any type The value for comparison. |
- Returns
-
non-null firebase.firestore.Query
The created query.