Implement insert_or_replace (#45)

Co-authored-by: Dr. Patrick Urbanke <patrick@getml.com>

tests/sqlite/test_insert_or_replace.cpp

@@ -0,0 +1,60 @@
+#include <gtest/gtest.h>
+
+#include <rfl.hpp>
+#include <rfl/json.hpp>
+#include <sqlgen.hpp>
+#include <sqlgen/sqlite.hpp>
+#include <vector>
+
+namespace test_insert_or_replace {
+
+struct Person {
+  sqlgen::PrimaryKey<uint32_t> id;
+  std::string first_name;
+  std::string last_name;
+  int age;
+};
+
+TEST(sqlite, test_insert_or_replace) {
+  const auto people1 = std::vector<Person>(
+      {Person{
+           .id = 0, .first_name = "Homer", .last_name = "Simpson", .age = 45},
+       Person{.id = 1, .first_name = "Bart", .last_name = "Simpson", .age = 10},
+       Person{.id = 2, .first_name = "Lisa", .last_name = "Simpson", .age = 8},
+       Person{
+           .id = 3, .first_name = "Maggie", .last_name = "Simpson", .age = 0}});
+
+  const auto people2 = std::vector<Person>(
+      {Person{.id = 1, .first_name = "Bartholomew", .last_name = "Simpson", .age = 10},
+       Person{
+           .id = 3, .first_name = "Margaret", .last_name = "Simpson", .age = 1}});
+
+  const auto people3 = std::vector<Person>(
+      {Person{
+           .id = 0, .first_name = "Homer", .last_name = "Simpson", .age = 45},
+       Person{.id = 1, .first_name = "Bartholomew", .last_name = "Simpson", .age = 10},
+       Person{.id = 2, .first_name = "Lisa", .last_name = "Simpson", .age = 8},
+       Person{
+           .id = 3, .first_name = "Margaret", .last_name = "Simpson", .age = 1}});
+
+  using namespace sqlgen;
+  using namespace sqlgen::literals;
+
+  const auto people4 = sqlite::connect()
+                           .and_then(begin_transaction)
+                           .and_then(create_table<Person> | if_not_exists)
+                           .and_then(insert(people1))
+                           .and_then(commit)
+                           .and_then(begin_transaction)
+                           .and_then(insert_or_replace(people2))
+                           .and_then(commit)
+                           .and_then(sqlgen::read<std::vector<Person>> | order_by("id"_c))
+                           .value();
+
+  const auto json3 = rfl::json::write(people3);
+  const auto json4 = rfl::json::write(people4);
+
+  EXPECT_EQ(json3, json4);
+}
+
+}  // namespace test_insert_or_replace