Simplified where() to have one argument only

include/sqlpp11/from.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2016, Roland Bock
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,

include/sqlpp11/functions.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2016, Roland Bock
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -42,19 +42,12 @@
 #include <sqlpp11/value_type.h>
 #include <sqlpp11/verbatim.h>  // Csaba Csoma suggests: unsafe_sql instead of verbatim
 #include <sqlpp11/verbatim_table.h>
+#include <sqlpp11/value.h>
 #include <sqlpp11/value_or_null.h>
 #include <sqlpp11/eval.h>
 
 namespace sqlpp
 {
-  template <typename T>
-  auto value(T t) -> wrap_operand_t<T>
-  {
-    static_assert(is_wrapped_value_t<wrap_operand_t<T>>::value,
-                  "value() is to be called with non-sql-type like int, or string");
-    return {t};
-  }
-
   template <typename Expression, typename Db>
   auto flatten(const Expression& exp, Db& db) -> verbatim_t<value_type_of<Expression>>
   {

include/sqlpp11/having.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2016, Roland Bock
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -28,6 +28,7 @@
 #define SQLPP_HAVING_H
 
 #include <sqlpp11/type_traits.h>
+#include <sqlpp11/value.h>
 #include <sqlpp11/expression.h>
 #include <sqlpp11/interpret_tuple.h>
 #include <sqlpp11/interpretable_list.h>
@@ -234,6 +235,11 @@ namespace sqlpp
         return _having_impl<_database_t>(_check<Expression>{}, expression);
       }
 
+      auto dynamic_having() const -> _new_statement_t<_check<boolean_operand>, having_t<_database_t, boolean_operand>>
+      {
+        return dynamic_having(::sqlpp::value(true));
+      }
+
     private:
       template <typename Database, typename Expression>
       auto _having_impl(const std::false_type&, Expression expression) const -> bad_statement;

include/sqlpp11/value.h

@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2013-2016, Roland Bock
+ * 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 SQLPP_VALUE_H
+#define SQLPP_VALUE_H
+
+#include <sqlpp11/type_traits.h>
+
+namespace sqlpp
+{
+  template <typename T>
+  auto value(T t) -> wrap_operand_t<T>
+  {
+    static_assert(is_wrapped_value_t<wrap_operand_t<T>>::value,
+                  "value() is to be called with non-sql-type like int, or string");
+    return {t};
+  }
+}
+
+#endif

include/sqlpp11/verbatim_table.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2016, Roland Bock
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -27,6 +27,7 @@
 #ifndef SQLPP_VERBATIM_TABLE_H
 #define SQLPP_VERBATIM_TABLE_H
 
+#include <sqlpp11/table.h>
 #include <sqlpp11/data_types/no_value.h>
 
 namespace sqlpp

include/sqlpp11/where.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2016, Roland Bock
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,
@@ -29,6 +29,7 @@
 
 #include <sqlpp11/statement_fwd.h>
 #include <sqlpp11/type_traits.h>
+#include <sqlpp11/value.h>
 #include <sqlpp11/parameter_list.h>
 #include <sqlpp11/expression.h>
 #include <sqlpp11/interpret_tuple.h>
@@ -39,10 +40,10 @@
 namespace sqlpp
 {
   // WHERE DATA
-  template <typename Database, typename... Expressions>
+  template <typename Database, typename Expression>
   struct where_data_t
   {
-    where_data_t(Expressions... expressions) : _expressions(expressions...)
+    where_data_t(Expression expression) : _expression(expression)
     {
     }
 
@@ -52,7 +53,7 @@ namespace sqlpp
     where_data_t& operator=(where_data_t&&) = default;
     ~where_data_t() = default;
 
-    std::tuple<Expressions...> _expressions;
+    Expression _expression;
     interpretable_list_t<Database> _dynamic_expressions;
   };
 
@@ -61,16 +62,16 @@ namespace sqlpp
       "at least one expression in where() requires a table which is otherwise not known in the statement");
 
   // WHERE(EXPR)
-  template <typename Database, typename... Expressions>
+  template <typename Database, typename Expression>
   struct where_t
   {
     using _traits = make_traits<no_value_t, tag::is_where>;
-    using _nodes = detail::type_vector<Expressions...>;
+    using _nodes = detail::type_vector<Expression>;
 
     using _is_dynamic = is_database<Database>;
 
     // Data
-    using _data_t = where_data_t<Database, Expressions...>;
+    using _data_t = where_data_t<Database, Expression>;
 
     // Member implementation with data and methods
     template <typename Policies>
@@ -82,39 +83,39 @@ namespace sqlpp
       {
       }
 
-      template <typename Expression>
+      template <typename Expr>
-      void add_ntc(Expression expression)
+      void add_ntc(Expr expression)
       {
-        add<Expression, std::false_type>(expression);
+        add<Expr, std::false_type>(expression);
       }
 
-      template <typename Expression, typename TableCheckRequired = std::true_type>
+      template <typename Expr, typename TableCheckRequired = std::true_type>
-      void add(Expression expression)
+      void add(Expr expression)
       {
         static_assert(_is_dynamic::value, "where::add() can only be called for dynamic_where");
-        static_assert(is_expression_t<Expression>::value, "invalid expression argument in where::add()");
+        static_assert(is_expression_t<Expr>::value, "invalid expression argument in where::add()");
-        static_assert(is_boolean_t<Expression>::value, "invalid expression argument in where::add()");
+        static_assert(is_boolean_t<Expr>::value, "invalid expression argument in where::add()");
-        static_assert(not TableCheckRequired::value or Policies::template _no_unknown_tables<Expression>::value,
+        static_assert(not TableCheckRequired::value or Policies::template _no_unknown_tables<Expr>::value,
                       "expression uses tables unknown to this statement in where::add()");
-        static_assert(not contains_aggregate_function_t<Expression>::value,
+        static_assert(not contains_aggregate_function_t<Expr>::value,
                       "where expression must not contain aggregate functions");
-        using _serialize_check = sqlpp::serialize_check_t<typename Database::_serializer_context_t, Expression>;
+        using _serialize_check = sqlpp::serialize_check_t<typename Database::_serializer_context_t, Expr>;
         _serialize_check::_();
 
-        using ok = logic::all_t<_is_dynamic::value, is_expression_t<Expression>::value, _serialize_check::type::value>;
+        using ok = logic::all_t<_is_dynamic::value, is_expression_t<Expr>::value, _serialize_check::type::value>;
 
         _add_impl(expression, ok());  // dispatch to prevent compile messages after the static_assert
       }
 
     private:
-      template <typename Expression>
+      template <typename Expr>
-      void _add_impl(Expression expression, const std::true_type&)
+      void _add_impl(Expr expression, const std::true_type&)
       {
         return _data._dynamic_expressions.emplace_back(expression);
       }
 
-      template <typename Expression>
+      template <typename Expr>
-      void _add_impl(Expression expression, const std::false_type&);
+      void _add_impl(Expr expression, const std::false_type&);
 
     public:
       _data_t _data;
@@ -124,7 +125,7 @@ namespace sqlpp
     template <typename Policies>
     struct _base_t
     {
-      using _data_t = where_data_t<Database, Expressions...>;
+      using _data_t = where_data_t<Database, Expression>;
 
       // workaround for msvc bug https://connect.microsoft.com/VisualStudio/Feedback/Details/2173269
       template <typename... Args>
@@ -225,7 +226,6 @@ namespace sqlpp
                                "where() argument has to be an sqlpp boolean expression.");
   SQLPP_PORTABLE_STATIC_ASSERT(assert_where_no_aggregate_functions_t,
                                "at least one aggregate function used in where()");
-  SQLPP_PORTABLE_STATIC_ASSERT(assert_where_static_count_args_t, "missing argument in where()");
   SQLPP_PORTABLE_STATIC_ASSERT(assert_where_dynamic_statement_dynamic_t,
                                "dynamic_where() must not be called in a static statement");
 
@@ -240,30 +240,26 @@ namespace sqlpp
   //      static_check_t<logic::all_t<is_boolean_t<Expressions>::value...>::value, assert_where_boolean_expression_t>,
   //      static_check_t<logic::all_t<(not contains_aggregate_function_t<Expressions>::value)...>::value,
   //                     assert_where_no_aggregate_functions_t>>;
-  template <typename... Expressions>
+  template <typename Expression>
   struct check_where
   {
     using type = static_combined_check_t<
-        static_check_t<logic::all_t<is_not_cpp_bool_t<Expressions>::value...>::value, assert_where_not_cpp_bool_t>,
+        static_check_t<is_not_cpp_bool_t<Expression>::value, assert_where_not_cpp_bool_t>,
-        static_check_t<logic::all_t<detail::is_expression_impl<Expressions>::type::value...>::value,
+        static_check_t<is_expression_t<Expression>::value, assert_where_boolean_expression_t>,
-                       assert_where_boolean_expression_t>,
+        static_check_t<is_boolean_t<Expression>::value, assert_where_boolean_expression_t>,
-        static_check_t<logic::all_t<is_boolean_t<Expressions>::value...>::value, assert_where_boolean_expression_t>,
+        static_check_t<not contains_aggregate_function_t<Expression>::value, assert_where_no_aggregate_functions_t>>;
-        static_check_t<logic::all_t<(not detail::contains_aggregate_function_impl<Expressions>::type::value)...>::value,
-                       assert_where_no_aggregate_functions_t>>;
   };
 
-  template <typename... Expressions>
+  template <typename Expression>
-  using check_where_t = typename check_where<Expressions...>::type;
+  using check_where_t = typename check_where<Expression>::type;
 
-  template <typename... Expressions>
+  template <typename Expression>
-  using check_where_static_t =
+  using check_where_static_t = check_where_t<Expression>;
-      static_combined_check_t<check_where_t<Expressions...>,
-                              static_check_t<sizeof...(Expressions) != 0, assert_where_static_count_args_t>>;
 
-  template <typename Database, typename... Expressions>
+  template <typename Database, typename Expression>
   using check_where_dynamic_t = static_combined_check_t<
       static_check_t<not std::is_same<Database, void>::value, assert_where_dynamic_statement_dynamic_t>,
-      check_where_t<Expressions...>>;
+      check_where_t<Expression>>;
 
   // NO WHERE YET
   template <bool WhereRequired>
@@ -332,54 +328,58 @@ namespace sqlpp
         return {static_cast<const derived_statement_t<Policies>&>(*this), where_data_t<void, unconditional_t>{}};
       }
 
-      template <typename... Expressions>
+      template <typename Expression>
-      auto where(Expressions... expressions) const
+      auto where(Expression expression) const
-          -> _new_statement_t<check_where_static_t<Expressions...>, where_t<void, Expressions...>>
+          -> _new_statement_t<check_where_static_t<Expression>, where_t<void, Expression>>
       {
-        using Check = check_where_static_t<Expressions...>;
+        using Check = check_where_static_t<Expression>;
         Check{}._();
 
-        return _where_impl<void>(Check{}, expressions...);
+        return _where_impl<void>(Check{}, expression);
       }
 
-      template <typename... Expressions>
+      template <typename Expression>
-      auto dynamic_where(Expressions... expressions) const
+      auto dynamic_where(Expression expression) const
-          -> _new_statement_t<check_where_dynamic_t<_database_t, Expressions...>, where_t<_database_t, Expressions...>>
+          -> _new_statement_t<check_where_dynamic_t<_database_t, Expression>, where_t<_database_t, Expression>>
       {
-        using Check = check_where_dynamic_t<_database_t, Expressions...>;
+        using Check = check_where_dynamic_t<_database_t, Expression>;
         Check{}._();
 
-        return _where_impl<_database_t>(Check{}, expressions...);
+        return _where_impl<_database_t>(Check{}, expression);
+      }
+
+      auto dynamic_where() const -> _new_statement_t<check_where_dynamic_t<_database_t, boolean_operand>,
+                                                     where_t<_database_t, boolean_operand>>
+      {
+        return dynamic_where(::sqlpp::value(true));
       }
 
     private:
-      template <typename Database, typename... Expressions>
+      template <typename Database, typename Expression>
-      auto _where_impl(const std::false_type&, Expressions... expressions) const -> bad_statement;
+      auto _where_impl(const std::false_type&, Expression expression) const -> bad_statement;
 
-      template <typename Database, typename... Expressions>
+      template <typename Database, typename Expression>
-      auto _where_impl(const std::true_type&, Expressions... expressions) const
+      auto _where_impl(const std::true_type&, Expression expression) const
-          -> _new_statement_t<std::true_type, where_t<Database, Expressions...>>
+          -> _new_statement_t<std::true_type, where_t<Database, Expression>>
       {
         return {static_cast<const derived_statement_t<Policies>&>(*this),
-                where_data_t<Database, Expressions...>{expressions...}};
+                where_data_t<Database, Expression>{expression}};
       }
     };
   };
 
   // Interpreters
-  template <typename Context, typename Database, typename... Expressions>
+  template <typename Context, typename Database, typename Expression>
-  struct serializer_t<Context, where_data_t<Database, Expressions...>>
+  struct serializer_t<Context, where_data_t<Database, Expression>>
   {
-    using _serialize_check = serialize_check_of<Context, Expressions...>;
+    using _serialize_check = serialize_check_of<Context, Expression>;
-    using T = where_data_t<Database, Expressions...>;
+    using T = where_data_t<Database, Expression>;
 
     static Context& _(const T& t, Context& context)
     {
-      if (sizeof...(Expressions) == 0 and t._dynamic_expressions.empty())
-        return context;
       context << " WHERE ";
-      interpret_tuple(t._expressions, " AND ", context);
+      serialize(t._expression, context);
-      if (sizeof...(Expressions) and not t._dynamic_expressions.empty())
+      if (not t._dynamic_expressions.empty())
         context << " AND ";
       interpret_list(t._dynamic_expressions, " AND ", context);
       return context;

test_static_asserts/where.cpp

@@ -43,31 +43,31 @@ namespace
     T::_print_me_;
   }
 
-  template <typename Assert, typename... Expressions>
+  template <typename Assert, typename Expression>
-  void where_static_check(const Expressions&... expressions)
+  void where_static_check(const Expression& expression)
   {
-    using CheckResult = sqlpp::check_where_static_t<Expressions...>;
+    using CheckResult = sqlpp::check_where_static_t<Expression>;
     using ExpectedCheckResult = std::is_same<CheckResult, Assert>;
     print_type_on_error<CheckResult>(ExpectedCheckResult{});
     static_assert(ExpectedCheckResult::value, "Unexpected check result");
 
-    using ReturnType = decltype(remove_from(t).where(expressions...));
+    using ReturnType = decltype(remove_from(t).where(expression));
     using ExpectedReturnType =
         sqlpp::logic::all_t<Assert::value xor std::is_same<ReturnType, sqlpp::bad_statement>::value>;
     print_type_on_error<ReturnType>(ExpectedReturnType{});
     static_assert(ExpectedReturnType::value, "Unexpected return type");
   }
 
-  template <typename Assert, typename... Expressions>
+  template <typename Assert, typename Expression>
-  void where_dynamic_check(const Expressions&... expressions)
+  void where_dynamic_check(const Expression& expression)
   {
     static auto db = MockDb{};
-    using CheckResult = sqlpp::check_where_dynamic_t<decltype(db), Expressions...>;
+    using CheckResult = sqlpp::check_where_dynamic_t<decltype(db), Expression>;
     using ExpectedCheckResult = std::is_same<CheckResult, Assert>;
     print_type_on_error<CheckResult>(ExpectedCheckResult{});
     static_assert(ExpectedCheckResult::value, "Unexpected check result");
 
-    using ReturnType = decltype(dynamic_remove_from(db, t).dynamic_where(expressions...));
+    using ReturnType = decltype(dynamic_remove_from(db, t).dynamic_where(expression));
     using ExpectedReturnType =
         sqlpp::logic::all_t<Assert::value xor std::is_same<ReturnType, sqlpp::bad_statement>::value>;
     print_type_on_error<ReturnType>(ExpectedReturnType{});
@@ -80,9 +80,6 @@ namespace
     where_static_check<sqlpp::consistent_t>(t.gamma);
     where_static_check<sqlpp::consistent_t>(t.gamma == true);
 
-    // Try no expression
-    where_static_check<sqlpp::assert_where_static_count_args_t>();
-
     // Try assignment as condition
     where_static_check<sqlpp::assert_where_boolean_expression_t>(t.gamma = true);
 
@@ -110,7 +107,6 @@ namespace
   void dynamic_where()
   {
     // OK
-    where_dynamic_check<sqlpp::consistent_t>();
     where_dynamic_check<sqlpp::consistent_t>(t.gamma);
     where_dynamic_check<sqlpp::consistent_t>(t.gamma == true);
 
@@ -138,7 +134,7 @@ namespace
         case_when(count(t.alpha) > 0).then(t.gamma).else_(not t.gamma));
 
     // Try dynamic_where on a non-dynamic remove
-    using CheckResult = sqlpp::check_where_dynamic_t<void>;
+    using CheckResult = sqlpp::check_where_dynamic_t<void, sqlpp::boolean_operand>;
     using ExpectedCheckResult = std::is_same<CheckResult, sqlpp::assert_where_dynamic_statement_dynamic_t>;
     print_type_on_error<CheckResult>(ExpectedCheckResult{});
     static_assert(ExpectedCheckResult::value, "Unexpected check result");

tests/Remove.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2015, Roland Bock
+ * Copyright (c) 2013-2016, Roland Bock
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification,