From daa672e6f0bba749c27b5fc16557c60a8b0425f1 Mon Sep 17 00:00:00 2001
From: rbock <rbock@eudoxos.de>
Date: Sat, 25 May 2019 14:04:44 +0200
Subject: [PATCH] Fix joins with CTEs

---
 include/sqlpp11/cte.h      |  1 +
 include/sqlpp11/pre_join.h | 18 ++++++++++--------
 tests/With.cpp             | 19 +++++++++++++++++++
 3 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/include/sqlpp11/cte.h b/include/sqlpp11/cte.h
index 9b3d40d4..eaa1129e 100644
--- a/include/sqlpp11/cte.h
+++ b/include/sqlpp11/cte.h
@@ -163,6 +163,7 @@ namespace sqlpp
   {
     using _traits = make_traits<no_value_t, tag::is_cte, tag::is_table>;  // FIXME: is table? really?
     using _nodes = detail::type_vector<>;
+    using _provided_tables = detail::type_set<cte_t>;
     using _required_ctes = detail::make_joined_set_t<required_ctes_of<Statement>, detail::type_set<AliasProvider>>;
     using _parameters = parameters_of<Statement>;
 
diff --git a/include/sqlpp11/pre_join.h b/include/sqlpp11/pre_join.h
index 15270b09..975b5042 100644
--- a/include/sqlpp11/pre_join.h
+++ b/include/sqlpp11/pre_join.h
@@ -30,6 +30,7 @@
 #include <sqlpp11/join_types.h>
 #include <sqlpp11/noop.h>
 #include <sqlpp11/on.h>
+#include <sqlpp11/table_ref.h>
 
 namespace sqlpp
 {
@@ -154,7 +155,7 @@ namespace sqlpp
     auto join_impl(Check, Lhs lhs, Rhs rhs) -> inconsistent<Check>;
 
     template <typename JoinType, typename Lhs, typename Rhs>
-    auto join_impl(consistent_t, Lhs lhs, Rhs rhs) -> pre_join_t<JoinType, Lhs, Rhs>;
+    auto join_impl(consistent_t, Lhs lhs, Rhs rhs) -> pre_join_t<JoinType, from_table_t<Lhs>, from_table_t<Rhs>>;
 
     template <typename JoinType, typename Lhs, typename Rhs>
     auto join_impl(Lhs lhs, Rhs rhs) -> decltype(join_impl<JoinType>(check_pre_join_t<Lhs, Rhs>{}, lhs, rhs));
@@ -163,19 +164,19 @@ namespace sqlpp
   template <typename Lhs, typename Rhs>
   auto join(Lhs lhs, Rhs rhs) -> decltype(detail::join_impl<inner_join_t>(lhs, rhs))
   {
-    return {lhs, rhs};
+    return {from_table(lhs), from_table(rhs)};
   }
 
   template <typename Lhs, typename Rhs>
   auto inner_join(Lhs lhs, Rhs rhs) -> decltype(detail::join_impl<inner_join_t>(lhs, rhs))
   {
-    return {lhs, rhs};
+    return {from_table(lhs), from_table(rhs)};
   }
 
   template <typename Lhs, typename Rhs>
   auto left_outer_join(Lhs lhs, Rhs rhs) -> decltype(detail::join_impl<left_outer_join_t>(lhs, rhs))
   {
-    return {lhs, rhs};
+    return {from_table(lhs), from_table(rhs)};
   }
 
   template <typename Lhs, typename Rhs>
@@ -183,13 +184,13 @@ namespace sqlpp
   {
     check_pre_join_t<Lhs, Rhs>{};
 
-    return {lhs, rhs};
+    return {from_table(lhs), from_table(rhs)};
   }
 
   template <typename Lhs, typename Rhs>
   auto outer_join(Lhs lhs, Rhs rhs) -> decltype(detail::join_impl<outer_join_t>(lhs, rhs))
   {
-    return {lhs, rhs};
+    return {from_table(lhs), from_table(rhs)};
   }
 
   namespace detail
@@ -202,13 +203,14 @@ namespace sqlpp
         -> join_t<pre_join_t<cross_join_t, Lhs, Rhs>, on_t<unconditional_t>>;
 
     template <typename Lhs, typename Rhs>
-    auto cross_join_impl(Lhs lhs, Rhs rhs) -> decltype(cross_join_impl(check_pre_join_t<Lhs, Rhs>{}, lhs, rhs));
+    auto cross_join_impl(Lhs lhs, Rhs rhs)
+        -> decltype(cross_join_impl(check_pre_join_t<from_table_t<Lhs>, from_table_t<Rhs>>{}, lhs, rhs));
   }  // namespace detail
 
   template <typename Lhs, typename Rhs>
   auto cross_join(Lhs lhs, Rhs rhs) -> decltype(detail::cross_join_impl(lhs, rhs))
   {
-    return {pre_join_t<cross_join_t, Lhs, Rhs>{lhs, rhs}, {}};
+    return {pre_join_t<cross_join_t, from_table_t<Lhs>, from_table_t<Rhs>>{from_table(lhs), from_table(rhs)}, {}};
   }
 }  // namespace sqlpp
 
diff --git a/tests/With.cpp b/tests/With.cpp
index dae27867..fbd2995f 100644
--- a/tests/With.cpp
+++ b/tests/With.cpp
@@ -55,5 +55,24 @@ int With(int, char*[])
       sqlpp::cte(b).as(select(t.alpha.as(a)).from(t).unconditionally().union_all(select(sqlpp::value(123).as(a))));
   db(with(c)(select(all_of(c)).from(c).unconditionally()));
 
+  // recursive CTE with join
+  {
+    const auto selectBase = select(t.alpha, t.delta).from(t).where(t.alpha > 17);
+    const auto initialCte = ::sqlpp::cte(sqlpp::alias::a).as(selectBase);
+    const auto recursiveCte = initialCte.union_all(
+        select(t.alpha, t.delta).from(t.join(initialCte).on(t.alpha == initialCte.delta)).unconditionally());
+    const auto query = with(recursiveCte)(select(recursiveCte.alpha).from(recursiveCte).unconditionally());
+
+    ::MockDb::_serializer_context_t printer = {};
+    const auto serializedQuery = serialize(query, printer).str();
+    std::cout << serializedQuery << '\n';
+
+    auto db = MockDb{};
+    for (const auto& row : db(query))
+    {
+      std::cout << row.alpha;
+    }
+  }
+
   return 0;
 }