ExistsQuery specifies the configurations of an Exists query. An Exists query is also called a NULL query or NULL-value query. This query is used in sparse data to determine whether a column of a row exists. For example, you can query the rows in which the value of the address column is not empty.
Data structure
message ExistsQuery {
optional string field_name = 1;
}
Parameter | Type | Required | Description |
field_name | string | Yes | The name of the column. |