From 1d5caca52366f7db1e84d5e88a2931cb94caa3f1 Mon Sep 17 00:00:00 2001
From: Roland Bock <rbock@eudoxos.de>
Date: Sat, 2 Apr 2022 08:27:38 +0200
Subject: [PATCH] Allow value_or_null to be assigned to parameters (#435)

---
 include/sqlpp11/data_types/parameter_value_base.h | 11 +++++++++++
 include/sqlpp11/value_or_null.h                   |  3 ++-
 tests/core/usage/Insert.cpp                       |  8 ++++++++
 tests/mysql/usage/Prepared.cpp                    | 10 ++++++++++
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/include/sqlpp11/data_types/parameter_value_base.h b/include/sqlpp11/data_types/parameter_value_base.h
index c7e103d5..1e45388e 100644
--- a/include/sqlpp11/data_types/parameter_value_base.h
+++ b/include/sqlpp11/data_types/parameter_value_base.h
@@ -28,6 +28,7 @@
 #define SQLPP11_DATA_TYPES_PARAMETER_VALUE_BASE_H
 
 #include <sqlpp11/data_types/parameter_value.h>
+#include <sqlpp11/value_or_null.h>
 
 namespace sqlpp
 {
@@ -53,6 +54,16 @@ namespace sqlpp
       return *this;
     }
 
+    parameter_value_base& operator=(const value_or_null_t<DataType>& val)
+    {
+      if (val._is_null)
+      {
+        set_null();
+        return *this;
+      }
+      return operator=(val._value);
+    }
+
     void set_null()
     {
       _value = {};
diff --git a/include/sqlpp11/value_or_null.h b/include/sqlpp11/value_or_null.h
index 5360dac7..52c3f10d 100644
--- a/include/sqlpp11/value_or_null.h
+++ b/include/sqlpp11/value_or_null.h
@@ -27,8 +27,9 @@
 #ifndef SQLPP11_VALUE_OR_NULL_H
 #define SQLPP11_VALUE_OR_NULL_H
 
-#include <sqlpp11/wrap_operand.h>
+#include <sqlpp11/null.h>
 #include <sqlpp11/type_traits.h>
+#include <sqlpp11/wrap_operand.h>
 
 namespace sqlpp
 {
diff --git a/tests/core/usage/Insert.cpp b/tests/core/usage/Insert.cpp
index 166133bc..f70ff1b3 100644
--- a/tests/core/usage/Insert.cpp
+++ b/tests/core/usage/Insert.cpp
@@ -95,5 +95,13 @@ int Insert(int, char*[])
   db(insert_into(t).set(t.gamma = true, t.delta = 0));
   db(insert_into(t).set(values()));
 
+  auto prepared_insert = db.prepare(insert_into(t).set(t.gamma = parameter(t.gamma), t.delta = parameter(t.delta)));
+  prepared_insert.params.gamma = true;
+  prepared_insert.params.delta = sqlpp::null;
+  prepared_insert.params.delta = 17;
+  prepared_insert.params.delta = sqlpp::value_or_null<sqlpp::integer>(sqlpp::null);
+  prepared_insert.params.delta = sqlpp::value_or_null(17);
+  db(prepared_insert);
+
   return 0;
 }
diff --git a/tests/mysql/usage/Prepared.cpp b/tests/mysql/usage/Prepared.cpp
index dab86a69..d277ec81 100644
--- a/tests/mysql/usage/Prepared.cpp
+++ b/tests/mysql/usage/Prepared.cpp
@@ -44,6 +44,16 @@ const auto tab = TabSample{};
 
 void testPreparedStatementResult(sql::connection& db)
 {
+  auto preparedInsert = db.prepare(insert_into(tab).set(tab.beta = parameter(tab.beta)));
+  preparedInsert.params.beta = sqlpp::null;
+  db(preparedInsert);
+  preparedInsert.params.beta = "17";
+  db(preparedInsert);
+  preparedInsert.params.beta = sqlpp::value_or_null<sqlpp::text>(sqlpp::null);
+  db(preparedInsert);
+  preparedInsert.params.beta = sqlpp::value_or_null("17");
+  db(preparedInsert);
+
   auto preparedSelectAll = db.prepare(sqlpp::select(count(tab.alpha)).from(tab).unconditionally());
   auto preparedUpdateAll = db.prepare(sqlpp::update(tab).set(tab.gamma = false).unconditionally());