handle many-to-many relations separately when process entities

include/matador/sql/column_definition_generator.hpp

@@ -42,9 +42,11 @@ public:
   template<class Pointer>
   void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, const utils::foreign_attributes &/*attr*/) {}
+  void on_has_many(ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const utils::foreign_attributes &/*attr*/) {}
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
 
 private:
   data_type_t type_{};
@@ -92,9 +94,11 @@ public:
     columns_.push_back(fk_column_generator_.generate(id, *x, ref_table, ref_column));
   }
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, const utils::foreign_attributes &/*attr*/) {}
+  void on_has_many(ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const utils::foreign_attributes &/*attr*/) {}
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
 
 private:
   std::pair<std::string, std::string> determine_foreign_ref(const std::type_index &ti);

include/matador/sql/column_generator.hpp

@@ -86,7 +86,7 @@ public:
     }
   }
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, const utils::foreign_attributes &attr)
+  void on_has_many(ContainerType &, const char *, const utils::foreign_attributes &attr)
   {
     if (attr.fetch() == utils::fetch_type::LAZY || force_lazy_) {
       return;
@@ -101,10 +101,15 @@ public:
     matador::utils::access::process(*this, obj);
     table_name_stack_.pop();
   }
+
   template<class ContainerType>
-  void on_has_many(const char *id, ContainerType &c, const utils::foreign_attributes &attr)
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &attr)
+  {
+  }
+
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &attr)
   {
-    on_has_many(id, c, "", "", attr);
   }
 
 private:

include/matador/sql/entity_query_builder.hpp

@@ -2,6 +2,7 @@
 #define QUERY_ENTITY_QUERY_BUILDER_HPP
 
 #include "matador/sql/connection.hpp"
+#include "matador/sql/condition.hpp"
 #include "matador/sql/query_context.hpp"
 #include "matador/sql/query.hpp"
 #include "matador/sql/query_intermediates.hpp"
@@ -10,6 +11,19 @@
 
 namespace matador::sql {
 
+struct join_data
+{
+  table join_table;
+  std::unique_ptr<basic_condition> condition;
+};
+
+struct entity_query_data {
+  std::string root_table_name;
+  std::vector<column> columns;
+  std::vector<join_data> joins;
+  std::unique_ptr<basic_condition> where_clause;
+};
+
 template < typename PrimaryKeyType >
 class entity_query_builder
 {
@@ -18,95 +32,172 @@ public:
   : pk_(pk)
   , schema_(scm) {}
 
-  // determine pk
-  // collect eager relations for joins
   template<class EntityType>
-  std::optional<query_context> build(connection &db) {
-    EntityType obj;
-    matador::utils::access::process(*this, obj);
-
+  std::optional<entity_query_data> build() {
     const auto info = schema_.info<EntityType>();
     if (!info) {
       return std::nullopt;
     }
-    columns_.clear();
-    table_name_ = info.value().name;
-    query q(db, schema_);
-    return q.select(column_generator::generate<EntityType>(schema_)).from({table_name_}).build();
-//    auto from_intermediate = q.select<EntityType>().from({"t"});
-//    return {};
+    table_info_stack_.push(info.value());
+    entity_query_data_ = { info->name };
+    EntityType obj;
+    matador::utils::access::process(*this, obj);
+
+    return std::move(entity_query_data_);
   }
 
   template < class V >
   void on_primary_key(const char *id, V &, typename std::enable_if<std::is_integral<V>::value && !std::is_same<bool, V>::value>::type* = 0)
   {
-    auto b = std::is_integral_v<PrimaryKeyType>;
-    std::cout << "is matching primary key: " << std::boolalpha << b << "\n";
-    columns_.emplace_back(table_name_, id, "");
+    push(id);
+    if (is_root_entity() && std::is_integral_v<PrimaryKeyType>) {
+      entity_query_data_.where_clause = make_condition(column{table_info_stack_.top().name, id, ""} == pk_);
+    }
   }
 
   void on_primary_key(const char *id, std::string &, size_t)
   {
-    auto b = std::is_same_v<PrimaryKeyType, std::string>;
-    std::cout << "is matching primary key: " << std::boolalpha << b << "\n";
-    columns_.emplace_back(table_name_, id, "");
+    push(id);
+    if (!is_root_entity()) {
+      auto b = std::is_same_v<PrimaryKeyType, std::string>;
+      std::cout << "is matching primary key: " << std::boolalpha << b << "\n";
+    }
   }
 
   void on_revision(const char *id, unsigned long long &/*rev*/)
   {
-    columns_.emplace_back(table_name_, id, "");
+    push(id);
   }
 
   template<typename Type>
   void on_attribute(const char *id, Type &, const utils::field_attributes &/*attr*/ = utils::null_attributes)
   {
-    columns_.emplace_back(table_name_, id, "");
+    push(id);
   }
 
   template<class Pointer>
   void on_belongs_to(const char *id, Pointer &, const utils::foreign_attributes &attr)
   {
     if (attr.fetch() == utils::fetch_type::EAGER) {
-      column col{id};
+      const auto info = schema_.info<typename Pointer::value_type>();
+      if (!info) {
+        return;
+      }
+      table_info_stack_.push(info.value());
+      typename Pointer::value_type obj;
+      matador::utils::access::process(*this , obj);
+      table_info_stack_.pop();
 
-      // collect join information (determine primary key of foreign entity)
+      auto pk = info->prototype.primary_key();
+      if (!pk) {
+        // error, prototype doesn't has a pk
+        return;
+      }
+      append_join({table_info_stack_.top().name, id}, {info->name, pk->name()});
+    } else {
+      push(id);
     }
-    columns_.emplace_back(table_name_, id, "");
   }
 
   template<class Pointer>
   void on_has_one(const char *id, Pointer &, const utils::foreign_attributes &attr)
   {
     if (attr.fetch() == utils::fetch_type::EAGER) {
-      auto info = schema_.info<typename Pointer::value_type>();
-      if (info) {
-        column lcol(table_name_, id, "");
-//        column rcol(info.value())
+      const auto info = schema_.info<typename Pointer::value_type>();
+      if (!info) {
+        return;
       }
-      // collect join information
+      table_info_stack_.push(info.value());
+      typename Pointer::value_type obj;
+      matador::utils::access::process(*this, obj);
+      table_info_stack_.pop();
+
+      auto pk = info->prototype.primary_key();
+      if (!pk) {
+        // error, prototype doesn't has a pk
+        return;
+      }
+      append_join({table_info_stack_.top().name, id}, {info->name, pk->name()});
+    } else {
+      push(id);
     }
-    columns_.emplace_back(table_name_, id, "");
   }
 
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, const utils::foreign_attributes &attr)
+  void on_has_many(ContainerType &, const char *join_column, const utils::foreign_attributes &attr)
   {
     if (attr.fetch() == utils::fetch_type::EAGER) {
-      // collect join information
+      const auto info = schema_.info<typename ContainerType::value_type::value_type>();
+      if (!info) {
+        return;
+      }
+      table_info_stack_.push(info.value());
+      typename ContainerType::value_type::value_type obj;
+      matador::utils::access::process(*this , obj);
+      table_info_stack_.pop();
+
+      auto pk = info->prototype.primary_key();
+      if (!pk) {
+        // error, prototype doesn't has a pk
+        return;
+      }
+
+      append_join({table_info_stack_.top().name, table_info_stack_.top().prototype.primary_key()->name()}, {info->name, join_column});
     }
   }
 
   template<class ContainerType>
-  void on_has_many(const char *id, ContainerType &c, const utils::foreign_attributes &attr)
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &attr)
   {
-    on_has_many(id, c, "", "", attr);
+    if (attr.fetch() == utils::fetch_type::EAGER) {
+      const auto info = schema_.info<typename ContainerType::value_type::value_type>();
+      if (!info) {
+        return;
+      }
+      table_info_stack_.push(info.value());
+      typename ContainerType::value_type::value_type obj;
+      matador::utils::access::process(*this , obj);
+      table_info_stack_.pop();
+
+      auto pk = info->prototype.primary_key();
+      if (!pk) {
+        // error, prototype doesn't has a pk
+        return;
+      }
+
+      append_join({table_info_stack_.top().name, table_info_stack_.top().prototype.primary_key()->name()}, {id, join_column});
+      append_join({info->name, pk->name()}, {id, inverse_join_column});
+    }
   }
 
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
+
+private:
+  void push(const std::string &column_name)
+  {
+    char str[4];
+    snprintf(str, 4, "c%02d", ++column_index);
+    entity_query_data_.columns.emplace_back(table_info_stack_.top().name, column_name, str);
+  }
+
+  [[nodiscard]] bool is_root_entity() const {
+    return table_info_stack_.size() == 1;
+  }
+
+  void append_join(const column &left, const column &right)
+  {
+    entity_query_data_.joins.push_back({
+      { left.table },
+      make_condition(left == right)
+    });
+  }
 private:
   PrimaryKeyType pk_;
-  std::vector<column> columns_;
+  std::stack<table_info> table_info_stack_;
   const schema &schema_;
-  std::string table_name_;
+  entity_query_data entity_query_data_;
+  int column_index{0};
 };
 
 }

include/matador/sql/has_many_to_many_relation.hpp

@@ -0,0 +1,38 @@
+#ifndef QUERY_HAS_MANY_TO_MANY_RELATION_HPP
+#define QUERY_HAS_MANY_TO_MANY_RELATION_HPP
+
+#include "matador/sql/entity.hpp"
+
+#include "matador/utils/access.hpp"
+#include "matador/utils/foreign_attributes.hpp"
+
+namespace matador::sql {
+
+template < class LocalType, class ForeignType >
+class has_many_to_many_relation
+{
+public:
+  has_many_to_many_relation() = default;
+  has_many_to_many_relation(std::string local_name, std::string remote_name)
+  : local_name_(std::move(local_name))
+  , remote_name_(std::move(remote_name)) {}
+
+  template<class Operator>
+  void process(Operator &op) {
+    namespace field = matador::utils::access;
+    field::belongs_to(op, local_name_.c_str(), local_, utils::default_foreign_attributes);
+    field::belongs_to(op, remote_name_.c_str(), remote_, utils::default_foreign_attributes);
+  }
+
+  entity<LocalType> local() const { return local_; }
+  entity<LocalType> remote() const { return remote_; }
+
+private:
+  std::string local_name_;
+  std::string remote_name_;
+  sql::entity<LocalType> local_;
+  sql::entity<ForeignType> remote_;
+};
+
+}
+#endif //QUERY_HAS_MANY_TO_MANY_RELATION_HPP

include/matador/sql/query_intermediates.hpp

@@ -161,6 +161,10 @@ public:
   {
     return where_clause(std::make_unique<Condition>(std::move(cond)));
   }
+  query_where_intermediate where(std::unique_ptr<basic_condition> &&cond)
+  {
+    return where_clause(std::move(cond));
+  }
   query_group_by_intermediate group_by(const column &col);
   query_order_by_intermediate order_by(const column &col);
 
@@ -178,6 +182,10 @@ public:
   {
     return on_clause(std::make_unique<Condition>(std::move(cond)));
   }
+  query_on_intermediate on(std::unique_ptr<basic_condition> &&cond)
+  {
+    return on_clause(std::move(cond));
+  }
 
 private:
   query_on_intermediate on_clause(std::unique_ptr<basic_condition> &&cond);

include/matador/sql/query_result_impl.hpp

@@ -41,9 +41,11 @@ public:
   void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
 
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, const utils::foreign_attributes &/*attr*/) {}
+  void on_has_many(ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const utils::foreign_attributes &/*attr*/) {}
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
 
 private:
   size_t column_index_{};

include/matador/sql/schema.hpp

@@ -23,6 +23,7 @@ class schema
 {
 public:
   using repository = std::unordered_map<std::type_index, table_info>;
+  using repository_by_name = std::unordered_map<std::string, std::reference_wrapper<table_info>>;
   using iterator = repository::iterator;
   using const_iterator = repository::const_iterator;
 
@@ -50,6 +51,7 @@ public:
   }
 
   [[nodiscard]] std::optional<table_info> info(std::type_index ti) const;
+  [[nodiscard]] std::optional<table_info> info(const std::string &name) const;
 
   template<typename Type>
   [[nodiscard]] std::pair<std::string, std::string> reference() const
@@ -77,6 +79,7 @@ public:
 private:
   std::string name_;
   repository repository_;
+  repository_by_name repository_by_name_;
 };
 
 }

include/matador/sql/session.hpp

@@ -13,6 +13,100 @@ namespace matador::sql {
 
 class dialect;
 
+struct join_data
+{
+  table join_table;
+  std::unique_ptr<basic_condition> condition;
+};
+
+//class join_collector
+//{
+//private:
+//  explicit join_collector(const sql::schema &ts, std::vector<join_data> &joins)
+//  : table_schema_(ts)
+//  , joins_(joins) {}
+//
+//public:
+//  template < class Type >
+//  static std::vector<join_data> collect(const sql::schema &ts)
+//  {
+//    const auto info = ts.info<Type>();
+//    if (!info) {
+//      return {};
+//    }
+//    std::vector<join_data> joins;
+//    join_collector collector(ts, joins);
+//    Type obj;
+//    matador::utils::access::process(collector, obj);
+//    return joins;
+//  }
+//
+//  template < class PrimaryKeyType >
+//  void on_primary_key(const char *id, PrimaryKeyType &, typename std::enable_if<std::is_integral<PrimaryKeyType>::value && !std::is_same<bool, PrimaryKeyType>::value>::type* = 0) {}
+//  void on_primary_key(const char *id, std::string &, size_t) {}
+//  void on_revision(const char *id, unsigned long long &/*rev*/) {}
+//  template<typename Type>
+//  void on_attribute(const char *id, Type &, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
+//
+//  template<class Pointer>
+//  void on_belongs_to(const char *id, Pointer &, const utils::foreign_attributes &attr)
+//  {
+//    if (attr.fetch() == utils::fetch_type::LAZY) {
+//      push(id);
+//    } else {
+//      const auto info = table_schema_.info<typename Pointer::value_type>();
+//      if (!info) {
+//        return;
+//      }
+//      table_name_stack_.push(info.value().name);
+//      typename Pointer::value_type obj;
+//      matador::utils::access::process(*this, obj);
+//      table_name_stack_.pop();
+//    }
+//  }
+//  template<class Pointer>
+//  void on_has_one(const char *id, Pointer &, const utils::foreign_attributes &attr)
+//  {
+//    if (attr.fetch() == utils::fetch_type::LAZY || force_lazy_) {
+//      push(id);
+//    } else {
+//      const auto info = table_schema_.info<typename Pointer::value_type>();
+//      if (!info) {
+//        return;
+//      }
+//      table_name_stack_.push(info.value().name);
+//      typename Pointer::value_type obj;
+//      matador::utils::access::process(*this, obj);
+//      table_name_stack_.pop();
+//    }
+//  }
+//  template<class ContainerType>
+//  void on_has_many(const char *, ContainerType &, const char *, const char *, const utils::foreign_attributes &attr)
+//  {
+//    if (attr.fetch() == utils::fetch_type::LAZY || force_lazy_) {
+//      return;
+//    }
+//    const auto info = table_schema_.info<typename ContainerType::value_type::value_type>();
+//    if (!info) {
+//      return;
+//    }
+//
+//    table_name_stack_.push(info.value().name);
+//    typename ContainerType::value_type::value_type obj;
+//    matador::utils::access::process(*this, obj);
+//    table_name_stack_.pop();
+//  }
+//  template<class ContainerType>
+//  void on_has_many(const char *id, ContainerType &c, const utils::foreign_attributes &attr)
+//  {
+//    on_has_many(id, c, "", "", attr);
+//  }
+//
+//private:
+//  const sql::schema &table_schema_;
+//  std::vector<join_data> &joins_;
+//};
+
 class session
 {
 public:
@@ -44,6 +138,9 @@ public:
       return {};
     }
 
+    auto columns = sql::column_generator::generate<Type>(*schema_);
+
+//    auto joins = sql
     c->query(*schema_).select({}).from(info->name);
     // build pk where condition
     // - check if type has pk

include/matador/sql/value_extractor.hpp

@@ -53,9 +53,11 @@ public:
     values_.emplace_back(fk_value_extractor_.extract(*x));
   }
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const char *, const char *, const utils::foreign_attributes &/*attr*/) {}
+  void on_has_many(ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
   template<class ContainerType>
-  void on_has_many(const char *, ContainerType &, const utils::foreign_attributes &/*attr*/) {}
+  void on_has_many_to_many(const char *id, ContainerType &c, const char *join_column, const char *inverse_join_column, const utils::foreign_attributes &/*attr*/) {}
+  template<class ContainerType>
+  void on_has_many_to_many(const char *id, ContainerType &c, const utils::foreign_attributes &/*attr*/) {}
 
 private:
   template<typename Type>