implemented query_builder::join and query_builder::on and added a test

test/QueryBuilderTest.cpp

@@ -174,4 +174,14 @@ TEST_CASE("Create, insert and select a blob column", "[query][blob]") {
 
   REQUIRE(q.sql == R"(SELECT "id", "name", "data" FROM "person")");
   REQUIRE(q.table_name == "person");
+}
+
+TEST_CASE("Select statement with join", "[query][join]") {
+  dialect d = dialect_builder::builder().create().build();
+  query_builder query(d);
+
+  auto q = query.select({"f.id", "ap.brand", "f.pilot_name"}).from("flight", "f").join("airplane", join_type_t::INNER, "ap").on("f.airplane_id", "ap.id").compile();
+
+  REQUIRE(q.sql == R"(SELECT "f.id", "ap.brand", "f.pilot_name" FROM "flight" AS "f" INNER JOIN "airplane" AS "ap" ON "f.airplane_id"="ap.id")");
+  REQUIRE(q.table_name == "flight");
 }