1 | #pragma once |
2 | |
3 | #include <DataTypes/DataTypeNullable.h> |
4 | #include <DataTypes/DataTypeNothing.h> |
5 | #include <Columns/IColumn.h> |
6 | #include <AggregateFunctions/IAggregateFunction.h> |
7 | |
8 | |
9 | namespace DB |
10 | { |
11 | |
12 | |
13 | /** Aggregate function that takes arbitrary number of arbitrary arguments and does nothing. |
14 | */ |
15 | class AggregateFunctionNothing final : public IAggregateFunctionHelper<AggregateFunctionNothing> |
16 | { |
17 | public: |
18 | AggregateFunctionNothing(const DataTypes & arguments, const Array & params) |
19 | : IAggregateFunctionHelper<AggregateFunctionNothing>(arguments, params) {} |
20 | |
21 | String getName() const override |
22 | { |
23 | return "nothing" ; |
24 | } |
25 | |
26 | DataTypePtr getReturnType() const override |
27 | { |
28 | return std::make_shared<DataTypeNullable>(std::make_shared<DataTypeNothing>()); |
29 | } |
30 | |
31 | void create(AggregateDataPtr) const override |
32 | { |
33 | } |
34 | |
35 | void destroy(AggregateDataPtr) const noexcept override |
36 | { |
37 | } |
38 | |
39 | bool hasTrivialDestructor() const override |
40 | { |
41 | return true; |
42 | } |
43 | |
44 | size_t sizeOfData() const override |
45 | { |
46 | return 0; |
47 | } |
48 | |
49 | size_t alignOfData() const override |
50 | { |
51 | return 1; |
52 | } |
53 | |
54 | void add(AggregateDataPtr, const IColumn **, size_t, Arena *) const override |
55 | { |
56 | } |
57 | |
58 | void merge(AggregateDataPtr, ConstAggregateDataPtr, Arena *) const override |
59 | { |
60 | } |
61 | |
62 | void serialize(ConstAggregateDataPtr, WriteBuffer &) const override |
63 | { |
64 | } |
65 | |
66 | void deserialize(AggregateDataPtr, ReadBuffer &, Arena *) const override |
67 | { |
68 | } |
69 | |
70 | void insertResultInto(ConstAggregateDataPtr, IColumn & to) const override |
71 | { |
72 | to.insertDefault(); |
73 | } |
74 | }; |
75 | |
76 | } |
77 | |