A split point that can be used in a query as a starting and/or end point for the query results. The cursors returned by and can only be used in a query that matches the constraint of query that produced this partition.
QueryPartition
Package
@google-cloud/firestoreConstructors
(constructor)(_firestore, _collectionId, _converter, _startAt, _endBefore)
constructor
(
_firestore
:
Firestore
,
_collectionId
:
string
,
_converter
:
firestore
.
FirestoreDataConverter<AppModelType
,
DbModelType
> ,
_startAt
:
api
.
IValue
[]
|
undefined
,
_endBefore
:
api
.
IValue
[]
|
undefined
);
Constructs a new instance of the QueryPartition
class
_firestore
_collectionId
string
_converter
FirebaseFirestore.FirestoreDataConverter
<AppModelType, DbModelType>
_startAt
google.firestore.v1.IValue
[] | undefined
_endBefore
google.firestore.v1.IValue
[] | undefined
Properties
endBefore
get
endBefore
()
:
unknown
[]
|
undefined
;
The cursor that defines the first result after this partition or undefined
if this is the last partition. The cursor value must be destructured when passed to endBefore()
(for example with query.endBefore(...queryPartition.endBefore)
).
const
query
=
firestore
.
collectionGroup
(
'collectionId'
);
for
await
(
const
partition
of
query
.
getPartitions
(
42
))
{
let
partitionedQuery
=
query
.
orderBy
(
FieldPath
.
documentId
());
if
(
partition
.
startAt
)
{
partitionedQuery
=
partitionedQuery
.
startAt
(...
partition
.
startAt
);
}
if
(
partition
.
endBefore
)
{
partitionedQuery
=
partitionedQuery
.
endBefore
(...
partition
.
endBefore
);
}
const
querySnapshot
=
await
partitionedQuery
.
get
();
console
.
log
(
`Partition contained
${
querySnapshot
.
length
}
documents`
);
}
{Array<*>} {Array<*>} A cursor value that can be used with or undefined
if this is the last partition.
startAt
get
startAt
()
:
unknown
[]
|
undefined
;
The cursor that defines the first result for this partition or undefined
if this is the first partition. The cursor value must be destructured when passed to startAt()
(for example with query.startAt(...queryPartition.startAt)
).
const
query
=
firestore
.
collectionGroup
(
'collectionId'
);
for
await
(
const
partition
of
query
.
getPartitions
(
42
))
{
let
partitionedQuery
=
query
.
orderBy
(
FieldPath
.
documentId
());
if
(
partition
.
startAt
)
{
partitionedQuery
=
partitionedQuery
.
startAt
(...
partition
.
startAt
);
}
if
(
partition
.
endBefore
)
{
partitionedQuery
=
partitionedQuery
.
endBefore
(...
partition
.
endBefore
);
}
const
querySnapshot
=
await
partitionedQuery
.
get
();
console
.
log
(
`Partition contained
${
querySnapshot
.
length
}
documents`
);
}
{Array<*>} {Array<*>} A cursor value that can be used with or undefined
if this is the first partition.
Methods
toQuery()
toQuery
()
:
Query<AppModelType
,
DbModelType
> ;
Returns a query that only encapsulates the documents for this partition.
const
query
=
firestore
.
collectionGroup
(
'collectionId'
);
for
await
(
const
partition
of
query
.
getPartitions
(
42
))
{
const
partitionedQuery
=
partition
.
toQuery
();
const
querySnapshot
=
await
partitionedQuery
.
get
();
console
.
log
(
`Partition contained
${
querySnapshot
.
length
}
documents`
);
}
{Query
