added query helper macro and join query parts

demo/macro_map.hpp

@@ -0,0 +1,42 @@
+#ifndef QUERY_MACRO_MAP_HPP
+#define QUERY_MACRO_MAP_HPP
+
+#define EVAL0(...) __VA_ARGS__
+#define EVAL1(...) EVAL0(EVAL0(EVAL0(__VA_ARGS__)))
+#define EVAL2(...) EVAL1(EVAL1(EVAL1(__VA_ARGS__)))
+#define EVAL3(...) EVAL2(EVAL2(EVAL2(__VA_ARGS__)))
+#define EVAL4(...) EVAL3(EVAL3(EVAL3(__VA_ARGS__)))
+#define EVAL(...)  EVAL4(EVAL4(EVAL4(__VA_ARGS__)))
+
+#define MAP_END(...)
+#define MAP_OUT
+#define MAP_COMMA ,
+
+#define MAP_GET_END2() 0, MAP_END
+#define MAP_GET_END1(...) MAP_GET_END2
+#define MAP_GET_END(...) MAP_GET_END1
+#define MAP_NEXT0(test, next, ...) next MAP_OUT
+#define MAP_NEXT1(test, next) MAP_NEXT0(test, next, 0)
+#define MAP_NEXT(test, next)  MAP_NEXT1(MAP_GET_END test, next)
+
+#define MAP0(f, x, peek, ...) f(x) MAP_NEXT(peek, MAP1)(f, peek, __VA_ARGS__)
+#define MAP1(f, x, peek, ...) f(x) MAP_NEXT(peek, MAP0)(f, peek, __VA_ARGS__)
+
+#define MAP_LIST_NEXT1(test, next) MAP_NEXT0(test, MAP_COMMA next, 0)
+#define MAP_LIST_NEXT(test, next)  MAP_LIST_NEXT1(MAP_GET_END test, next)
+
+#define MAP_LIST0(f, x, peek, ...) f(x) MAP_LIST_NEXT(peek, MAP_LIST1)(f, peek, __VA_ARGS__)
+#define MAP_LIST1(f, x, peek, ...) f(x) MAP_LIST_NEXT(peek, MAP_LIST0)(f, peek, __VA_ARGS__)
+
+/**
+ * Applies the function macro `f` to each of the remaining parameters.
+ */
+#define MAP(f, ...) EVAL(MAP1(f, __VA_ARGS__, ()()(), ()()(), ()()(), 0))
+
+/**
+ * Applies the function macro `f` to each of the remaining parameters and
+ * inserts commas between the results.
+ */
+#define MAP_LIST(f, ...) EVAL(MAP_LIST1(f, __VA_ARGS__, ()()(), ()()(), ()()(), 0))
+
+#endif //QUERY_MACRO_MAP_HPP

demo/main.cpp

@@ -6,6 +6,9 @@
 
 #include "matador/utils/access.hpp"
 
+#include "query_helper.hpp"
+
+#include <iostream>
 #include <string>
 
 struct author
@@ -46,26 +49,36 @@ struct book
   }
 };
 
+QUERY_HELPER(author, id, first_name, last_name, date_of_birth, year_of_birth, distinguished)
+QUERY_HELPER(book, id, book_author, title, published_in)
+
 int main()
 {
   using namespace matador::sql;
+
   const std::string env_var{"MATADOR_BACKENDS_PATH"};
 
   std::string dns{"sqlite://demo.db"};
 //  std::string dns{"memory://test"};
   auto s = std::make_shared<schema>();
+  s->attach<author>("authors");
+  s->attach<book>("books");
+
   connection c(dns, s);
 
   auto books = c.query()
-    .select<book>({"author.name"})
-    .from("book")
-    .join_left("author")
+    .select<book>({qh::book.id.name})
+    .from({"book"})
+    .join_left({"authors"})
     .on("book.author_id"_col == "author.id"_col)
     .where("book.published_in"_col < 2008 && "author.name"_col == "Michael Crichton")
     .order_by("book.title").asc()
     .offset(2)
     .limit(5)
-    .fetch_all<book>();
+    .str();
+//    .fetch_all<book>();
+
+  std::cout << "SQL: " << books << "\n";
 
   // SELECT book.title, book.id, book.author_id, book.published_in, author.name
   // FROM book

demo/query_helper.hpp

@@ -0,0 +1,52 @@
+#ifndef QUERY_QUERY_HELPER_HPP
+#define QUERY_QUERY_HELPER_HPP
+
+#include "macro_map.hpp"
+
+#include <string>
+#include <ostream>
+
+template<typename QueryClass>
+struct basic_query;
+
+struct table {
+  template<typename QueryClass>
+  table(const basic_query<QueryClass> &qc);
+  const std::string name;
+};
+
+struct field {
+  const std::string name;
+
+  friend std::ostream& operator<<(std::ostream &out, const field &f) {
+    out << f.name;
+    return out;
+  }
+};
+
+template<typename QueryClass>
+struct basic_query {
+  const table& operator()() const {
+    return table_;
+  }
+
+  const table table_;
+};
+
+template<typename QueryClass>
+table::table(const basic_query<QueryClass>&)
+: name(QueryClass::internal_table_name_) {
+}
+
+#define FIELD(x) const field x{#x};
+
+#define QUERY_HELPER(C, ...) \
+namespace qh {     \
+namespace internal {                      \
+struct C##_query {           \
+MAP(FIELD, __VA_ARGS__) \
+}; }                     \
+static const internal:: C##_query C;  \
+}
+
+#endif //QUERY_QUERY_HELPER_HPP