1 | //===----------------------------------------------------------------------===// |
---|---|
2 | // DuckDB |
3 | // |
4 | // duckdb/parser/expression/case_expression.hpp |
5 | // |
6 | // |
7 | //===----------------------------------------------------------------------===// |
8 | |
9 | #pragma once |
10 | |
11 | #include "duckdb/parser/parsed_expression.hpp" |
12 | #include "duckdb/common/vector.hpp" |
13 | |
14 | namespace duckdb { |
15 | |
16 | struct CaseCheck { |
17 | unique_ptr<ParsedExpression> when_expr; |
18 | unique_ptr<ParsedExpression> then_expr; |
19 | |
20 | void FormatSerialize(FormatSerializer &serializer) const; |
21 | static CaseCheck FormatDeserialize(FormatDeserializer &deserializer); |
22 | }; |
23 | |
24 | //! The CaseExpression represents a CASE expression in the query |
25 | class CaseExpression : public ParsedExpression { |
26 | public: |
27 | static constexpr const ExpressionClass TYPE = ExpressionClass::CASE; |
28 | |
29 | public: |
30 | DUCKDB_API CaseExpression(); |
31 | |
32 | vector<CaseCheck> case_checks; |
33 | unique_ptr<ParsedExpression> else_expr; |
34 | |
35 | public: |
36 | string ToString() const override; |
37 | |
38 | static bool Equal(const CaseExpression &a, const CaseExpression &b); |
39 | |
40 | unique_ptr<ParsedExpression> Copy() const override; |
41 | |
42 | void Serialize(FieldWriter &writer) const override; |
43 | static unique_ptr<ParsedExpression> Deserialize(ExpressionType type, FieldReader &source); |
44 | void FormatSerialize(FormatSerializer &serializer) const override; |
45 | static unique_ptr<ParsedExpression> FormatDeserialize(ExpressionType type, FormatDeserializer &deserializer); |
46 | |
47 | public: |
48 | template <class T, class BASE> |
49 | static string ToString(const T &entry) { |
50 | string case_str = "CASE "; |
51 | for (auto &check : entry.case_checks) { |
52 | case_str += " WHEN ("+ check.when_expr->ToString() + ")"; |
53 | case_str += " THEN ("+ check.then_expr->ToString() + ")"; |
54 | } |
55 | case_str += " ELSE "+ entry.else_expr->ToString(); |
56 | case_str += " END"; |
57 | return case_str; |
58 | } |
59 | }; |
60 | } // namespace duckdb |
61 |