Minimal over() implementation for aggregate functions (#316)

* Minimal over() implementation for aggregate functions

* auto_alias support for over()

* add missing typename

* Test .over() serialization

* Add missing return to test

* Fix testing over auto alias

Co-authored-by: Ben Maxwell <42680490+MaciumDue@users.noreply.github.com>

include/sqlpp11/aggregate_function_operators.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2013-2020, Roland Bock, MacDue
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ *   Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ *   Redistributions in binary form must reproduce the above copyright notice, this
+ *   list of conditions and the following disclaimer in the documentation and/or
+ *   other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef SQLPP11_AGGREGATE_FUNCTION_OPERATORS_H
+#define SQLPP11_AGGREGATE_FUNCTION_OPERATORS_H
+
+namespace sqlpp
+{
+  template <typename Expr>
+  struct aggregate_function_operators
+  {
+    over_t<Expr> over() const
+    {
+      return {*static_cast<const Expr*>(this)};
+    }
+  };
+}  // namespace sqlpp
+
+#endif
+

include/sqlpp11/aggregate_functions/avg.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2016, Roland Bock
+ * Copyright (c) 2013-2020, Roland Bock, MacDue
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -56,6 +56,7 @@ namespace sqlpp
 
   template <typename Flag, typename Expr>
   struct avg_t : public expression_operators<avg_t<Flag, Expr>, floating_point>,
+                 public aggregate_function_operators<avg_t<Flag, Expr>>,
                  public alias_operators<avg_t<Flag, Expr>>
   {
     using _traits = make_traits<floating_point, tag::is_expression, tag::is_selectable>;

include/sqlpp11/aggregate_functions/count.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2020, Roland Bock, MacDue
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -27,8 +27,10 @@
 #ifndef SQLPP11_AGGREGATE_FUNCTIONS_COUNT_H
 #define SQLPP11_AGGREGATE_FUNCTIONS_COUNT_H
 
+#include <sqlpp11/over.h>
 #include <sqlpp11/char_sequence.h>
 #include <sqlpp11/select_flags.h>
+#include <sqlpp11/aggregate_function_operators.h>
 #include <sqlpp11/data_types/integral/data_type.h>
 
 namespace sqlpp
@@ -57,6 +59,7 @@ namespace sqlpp
 
   template <typename Flag, typename Expr>
   struct count_t : public expression_operators<count_t<Flag, Expr>, integral>,
+                   public aggregate_function_operators<count_t<Flag, Expr>>,
                    public alias_operators<count_t<Flag, Expr>>
   {
     using _traits = make_traits<integral, tag::is_expression /*, tag::is_selectable*/>;

include/sqlpp11/aggregate_functions/max.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2020, Roland Bock, MacDue
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -55,7 +55,9 @@ namespace sqlpp
   };
 
   template <typename Expr>
-  struct max_t : public expression_operators<max_t<Expr>, value_type_of<Expr>>, public alias_operators<max_t<Expr>>
+  struct max_t : public expression_operators<max_t<Expr>, value_type_of<Expr>>,
+                 public aggregate_function_operators<max_t<Expr>>,
+                 public alias_operators<max_t<Expr>>
   {
     using _traits = make_traits<value_type_of<Expr>, tag::is_expression, tag::is_selectable>;
     using _nodes = detail::type_vector<Expr, aggregate_function>;

include/sqlpp11/aggregate_functions/min.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2020, Roland Bock, MacDue
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -55,7 +55,9 @@ namespace sqlpp
   };
 
   template <typename Expr>
-  struct min_t : public expression_operators<min_t<Expr>, value_type_of<Expr>>, public alias_operators<min_t<Expr>>
+  struct min_t : public expression_operators<min_t<Expr>, value_type_of<Expr>>,
+                 public aggregate_function_operators<min_t<Expr>>,
+                 public alias_operators<min_t<Expr>>
   {
     using _traits = make_traits<value_type_of<Expr>, tag::is_expression, tag::is_selectable>;
     using _nodes = detail::type_vector<Expr, aggregate_function>;

include/sqlpp11/aggregate_functions/sum.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2020, Roland Bock, MacDue
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -56,6 +56,7 @@ namespace sqlpp
 
   template <typename Flag, typename Expr>
   struct sum_t : public expression_operators<sum_t<Flag, Expr>, value_type_of<Expr>>,
+                 public aggregate_function_operators<sum_t<Flag, Expr>>,
                  public alias_operators<sum_t<Flag, Expr>>
   {
     using _traits = make_traits<value_type_of<Expr>, tag::is_expression, tag::is_selectable>;

include/sqlpp11/over.h

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2013-2020, Roland Bock, MacDue
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ *   Redistributions of source code must retain the above copyright notice, this
+ *   list of conditions and the following disclaimer.
+ *
+ *   Redistributions in binary form must reproduce the above copyright notice, this
+ *   list of conditions and the following disclaimer in the documentation and/or
+ *   other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef SQLPP11_OVER_H
+#define SQLPP11_OVER_H
+
+#include <sqlpp11/type_traits.h>
+#include <sqlpp11/serializer.h>
+
+namespace sqlpp
+{
+  template <typename AggregateExpr>
+  struct over_t : public expression_operators<over_t<AggregateExpr>, integral>,
+                  public alias_operators<over_t<AggregateExpr>>
+  {
+    using _traits = make_traits<integral, tag::is_expression>;
+    using _nodes = detail::type_vector<AggregateExpr, aggregate_function>;
+
+    using _auto_alias_t = typename AggregateExpr::_auto_alias_t;
+
+    over_t(AggregateExpr aggregate_expression)
+      : _aggregate_expression(aggregate_expression)
+    {
+    }
+
+    over_t(const over_t&) = default;
+    over_t(over_t&&) = default;
+    over_t& operator=(const over_t&) = default;
+    over_t& operator=(over_t&&) = default;
+    ~over_t() = default;
+
+    AggregateExpr _aggregate_expression;
+  };
+
+  template <typename Context, typename AggregateExpr>
+  struct serializer_t<Context, over_t<AggregateExpr>>
+  {
+    using _serialize_check = serialize_check_of<Context, AggregateExpr>;
+    using T = over_t<AggregateExpr>;
+
+    static Context& _(const T& t, Context& context)
+    {
+      serialize_operand(t._aggregate_expression, context);
+      context << " OVER()";
+      return context;
+    }
+  };
+}  // namespace sqlpp
+
+#endif

test_serializer/CMakeLists.txt

@@ -27,12 +27,13 @@ set(test_serializer_names
 	Blob
 	CustomQuery
 	DynamicWhere
-	ForUpdate
+  ForUpdate
-	From
+  From
-	In
+  In
-	Insert
+  Insert
-	TableAlias
+  Over
-	Where
+  TableAlias
+  Where
   )
 
 create_test_sourcelist(test_serializer_sources test_serializer_main.cpp ${test_serializer_names})

test_serializer/Over.cpp

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2016-2020, Roland Bock, MacDue
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "Sample.h"
+#include "compare.h"
+#include <sqlpp11/sqlpp11.h>
+
+SQLPP_ALIAS_PROVIDER(dueutil)
+
+int Over(int, char* []) {
+  auto const foo = test::TabFoo{};
+
+  // no/auto alias (wrapped in select so alias is applied)
+  compare(__LINE__, select(avg(foo.omega).over()), "SELECT AVG(tab_foo.omega) OVER() AS avg_");
+  compare(__LINE__, select(count(foo.omega).over()), "SELECT COUNT(tab_foo.omega) OVER() AS count_");
+  compare(__LINE__, select(max(foo.omega).over()), "SELECT MAX(tab_foo.omega) OVER() AS max_");
+  compare(__LINE__, select(min(foo.omega).over()), "SELECT MIN(tab_foo.omega) OVER() AS min_");
+  compare(__LINE__, select(sum(foo.omega).over()), "SELECT SUM(tab_foo.omega) OVER() AS sum_");
+
+  // alias
+  compare(__LINE__, avg(foo.omega).over().as(dueutil), "AVG(tab_foo.omega) OVER() AS dueutil");
+  compare(__LINE__, count(foo.omega).over().as(dueutil), "COUNT(tab_foo.omega) OVER() AS dueutil");
+  compare(__LINE__, max(foo.omega).over().as(dueutil), "MAX(tab_foo.omega) OVER() AS dueutil");
+  compare(__LINE__, min(foo.omega).over().as(dueutil), "MIN(tab_foo.omega) OVER() AS dueutil");
+  compare(__LINE__, sum(foo.omega).over().as(dueutil), "SUM(tab_foo.omega) OVER() AS dueutil");
+
+  return 0;
+}