/// <summary>
/// Add a filter for the given field path.
/// </summary>
/// <remarks>
/// This call adds additional filters to any previously-specified ones.
/// </remarks>
/// <param name="fieldPath">The field path to filter on. Must not be null.</param>
/// <param name="op">The filter operator.</param>
/// <param name="value">The value to compare in the filter.</param>
/// <returns>A new query based on the current one, but with the additional specified filter applied.</returns>
public Query Where(FieldPath fieldPath, QueryOperator op, object value)
{
FieldOp queryOp = GetOperator(op);
var unaryOperator = GetUnaryOperator(value);
Filter filter;
if (unaryOperator != UnaryFilter.Types.Operator.Unspecified)
{
if (queryOp == FieldOp.Equal)
{
filter = new Filter {
UnaryFilter = new UnaryFilter {
Field = fieldPath.ToFieldReference(), Op = unaryOperator
}
};
}
else
{
throw new ArgumentException(nameof(value), "null and NaN values can only be used with the Equal operator");
}
}
else
{
var convertedValue = ValueSerializer.Serialize(value);
filter = new Filter {
FieldFilter = new FieldFilter {
Field = fieldPath.ToFieldReference(), Op = queryOp, Value = convertedValue
}
};
}
return(WithFilter(filter));
}
private Query OrderBy(FieldPath fieldPath, Direction direction)
{
GaxPreconditions.CheckState(QueryProto.StartAt == null && QueryProto.EndAt == null,
"All orderings must be specified before StartAt, StartAfter, EndBefore or EndAt are called.");
var query = QueryProto.Clone();
query.OrderBy.Add(new Order {
Field = fieldPath.ToFieldReference(), Direction = direction
});
return(WithQuery(query));
}