1 | #pragma once |
---|---|
2 | |
3 | #include <Columns/IColumnDummy.h> |
4 | #include <Core/Field.h> |
5 | |
6 | |
7 | namespace DB |
8 | { |
9 | |
10 | class Set; |
11 | using ConstSetPtr = std::shared_ptr<const Set>; |
12 | |
13 | |
14 | /** A column containing multiple values in the `IN` section. |
15 | * Behaves like a constant-column (because the set is one, not its own for each line). |
16 | * This column has a nonstandard value, so it can not be obtained via a normal interface. |
17 | */ |
18 | class ColumnSet final : public COWHelper<IColumnDummy, ColumnSet> |
19 | { |
20 | private: |
21 | friend class COWHelper<IColumnDummy, ColumnSet>; |
22 | |
23 | ColumnSet(size_t s_, const ConstSetPtr & data_) : data(data_) { s = s_; } |
24 | ColumnSet(const ColumnSet &) = default; |
25 | |
26 | public: |
27 | const char * getFamilyName() const override { return "Set"; } |
28 | MutableColumnPtr cloneDummy(size_t s_) const override { return ColumnSet::create(s_, data); } |
29 | |
30 | ConstSetPtr getData() const { return data; } |
31 | |
32 | // Used only for debugging, making it DUMPABLE |
33 | Field operator[](size_t) const override { return {}; } |
34 | |
35 | private: |
36 | ConstSetPtr data; |
37 | }; |
38 | |
39 | } |
40 |