public abstract class AggregateField
Represents an aggregation that can be performed by Firestore.
Static Methods
average(FieldPath fieldPath)
public static AggregateField.AverageAggregateField average(FieldPath fieldPath)
Create an AverageAggregateField 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.
Parameter | |
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Name | Description |
fieldPath | FieldPath Specifies the field to average across the result set. |
Returns | |
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Type | Description |
AggregateField.AverageAggregateField | The |
average(String field)
public static AggregateField.AverageAggregateField average(String field)
Create an AverageAggregateField 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.
Parameter | |
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Name | Description |
field | String Specifies the field to average across the result set. |
Returns | |
---|---|
Type | Description |
AggregateField.AverageAggregateField | The |
count()
public static AggregateField.CountAggregateField count()
Create a CountAggregateField 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.
Returns | |
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Type | Description |
AggregateField.CountAggregateField | The |
sum(FieldPath fieldPath)
public static AggregateField.SumAggregateField sum(FieldPath fieldPath)
Create a SumAggregateField 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.
Parameter | |
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Name | Description |
fieldPath | FieldPath Specifies the field to sum across the result set. |
Returns | |
---|---|
Type | Description |
AggregateField.SumAggregateField | The |
sum(String field)
public static AggregateField.SumAggregateField sum(String field)
Create a SumAggregateField 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.
Parameter | |
---|---|
Name | Description |
field | String Specifies the field to sum across the result set. |
Returns | |
---|---|
Type | Description |
AggregateField.SumAggregateField | The |
Constructors
AggregateField()
public AggregateField()
Methods
equals(Object other)
public boolean equals(Object other)
Returns true if the given object is equal to this object. Two AggregateField
objects are
considered equal if they have the same operator and operate on the same field.
Parameter | |
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Name | Description |
other | Object |
Returns | |
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Type | Description |
boolean |
hashCode()
public int hashCode()
Calculates and returns the hash code for this object.
Returns | |
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Type | Description |
int |