join.hpp

#pragma once
 
#include <initializer_list>
#include <iron_query/condition.hpp>
#include <iron_query/virtual_table.hpp>
#include <string>
#include <string_view>
 
namespace iron_query {
 
struct [[nodiscard]] JoinKind {
  virtual std::string_view ToString() const = 0;
 
  virtual bool IsNatural() const { return false; }
};
 
struct [[nodiscard]] Inner final : JoinKind {
  std::string_view ToString() const override;
};
struct [[nodiscard]] Cross final : JoinKind {
  std::string_view ToString() const override;
};
struct [[nodiscard]] LeftOuter final : JoinKind {
  std::string_view ToString() const override;
};
struct [[nodiscard]] RightOuter final : JoinKind {
  std::string_view ToString() const override;
};
struct [[nodiscard]] FullOuter final : JoinKind {
  std::string_view ToString() const override;
};
struct [[nodiscard]] NaturalInner final : JoinKind {
  std::string_view ToString() const override;
  bool IsNatural() const override { return true; }
};
struct [[nodiscard]] NaturalLeftOuter final : JoinKind {
  std::string_view ToString() const override;
  bool IsNatural() const override { return true; }
};
struct [[nodiscard]] NaturalRightOuter final : JoinKind {
  std::string_view ToString() const override;
  bool IsNatural() const override { return true; }
};
struct [[nodiscard]] NaturalFullOuter final : JoinKind {
  std::string_view ToString() const override;
  bool IsNatural() const override { return true; }
};
 
class [[nodiscard]] Join final : public VirtualTable {
public:
  Join(const VirtualTable &a, const VirtualTable &b, const JoinKind &kind);
 
  Join On(Condition exp) &&;
 
  Join Using(std::initializer_list<Expr> columns) &&;
 
  std::string ToString() const override;
 
  std::string ToStringAsFromItem() const override;
 
private:
  std::string a_, b_;
  std::string kind_;
  bool natural_;
  std::string on_;
  std::string using_;
};
 
} // namespace iron_query