| 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 |