FIRAggregateField
@interface FIRAggregateField : NSObject
Represents an aggregation that can be performed by Firestore.
-
Create an
AggregateField
object that can be used to compute the count of documents in the result set of a query.The result of a count operation will always be a 64-bit integer value.
Declaration
Objective-C
+ (nonnull instancetype)aggregateFieldForCount;
Return Value
AggregateField
object that can be used to compute the count of documents in the result set of a query. -
Create an
AggregateField
object that can be used to compute the sum of a specified field over a range of documents in the result set of a query.The result of a sum operation will always be a 64-bit integer value, a double, or NaN.
- Summing over zero documents or fields will result in 0L.
- Summing over NaN will result in a double value representing NaN.
- A sum that overflows the maximum representable 64-bit integer value will result in a double return value. This may result in lost precision of the result.
A sum that overflows the maximum representable double value will result in a double return value representing infinity.
Declaration
Objective-C
+ (nonnull instancetype)aggregateFieldForSumOfField:(nonnull NSString *)field;
Parameters
field
Specifies the field to sum across the result set.
Return Value
AggregateField
object that can be used to compute the sum of a specified field over a range of documents in the result set of a query. -
Create an
AggregateField
object that can be used to compute the sum of a specified field over a range of documents in the result set of a query.The result of a sum operation will always be a 64-bit integer value, a double, or NaN.
- Summing over zero documents or fields will result in 0L.
- Summing over NaN will result in a double value representing NaN.
- A sum that overflows the maximum representable 64-bit integer value will result in a double return value. This may result in lost precision of the result.
A sum that overflows the maximum representable double value will result in a double return value representing infinity.
Declaration
Objective-C
+ (nonnull instancetype)aggregateFieldForSumOfFieldPath: (nonnull FIRFieldPath *)fieldPath;
Parameters
fieldPath
Specifies the field to sum across the result set.
Return Value
AggregateField
object that can be used to compute the sum of a specified field over a range of documents in the result set of a query. -
Create an
AggregateField
object that can be used to compute the average of a specified field over a range of documents in the result set of a query.The result of an average operation will always be a double or NaN.
- Averaging over zero documents or fields will result in a double value representing NaN.
Averaging over NaN will result in a double value representing NaN.
Declaration
Objective-C
+ (nonnull instancetype)aggregateFieldForAverageOfField: (nonnull NSString *)field;
Parameters
field
Specifies the field to average across the result set.
Return Value
AggregateField
object that can be used to compute the average of a specified field over a range of documents in the result set of a query. -
Create an
AggregateField
object that can be used to compute the average of a specified field over a range of documents in the result set of a query.The result of an average operation will always be a double or NaN.
- Averaging over zero documents or fields will result in a double value representing NaN.
Averaging over NaN will result in a double value representing NaN.
Declaration
Objective-C
+ (nonnull instancetype)aggregateFieldForAverageOfFieldPath: (nonnull FIRFieldPath *)fieldPath;
Parameters
fieldPath
Specifies the field to average across the result set.
Return Value
AggregateField
object that can be used to compute the average of a specified field over a range of documents in the result set of a query.