# Class Sum

Sum of the values of the requested field. * Only numeric values will be aggregated. All non-numeric values
including `NULL`

are skipped. * If the aggregated values contain `NaN`

, returns `NaN`

. Infinity math follows
IEEE-754 standards. * If the aggregated value set is empty, returns 0. * Returns a 64-bit integer if all
aggregated numbers are integers and the sum result does not overflow. Otherwise, the result is returned as a
double. Note that even if all the aggregated values are integers, the result is returned as a double if it
cannot fit within a 64-bit signed integer. When this occurs, the returned value will lose precision. * When
underflow occurs, floating-point aggregation is non-deterministic. This means that running the same query
repeatedly without any changes to the underlying values could produce slightly different results each time. In
those cases, values should be stored as integers over floating-point numbers.

##### Implements

##### Inherited Members

**Namespace**: Google.Apis.Firestore.v1.Data

**Assembly**: Google.Apis.Firestore.v1.dll

##### Syntax

`public class Sum : IDirectResponseSchema`

### Properties

#### ETag

The ETag of the item.

##### Declaration

`public virtual string ETag { get; set; }`

##### Property Value

Type | Description |
---|---|

string |

#### Field

The field to aggregate on.

##### Declaration

```
[JsonProperty("field")]
public virtual FieldReference Field { get; set; }
```

##### Property Value

Type | Description |
---|---|

FieldReference |