pk generator progress and sequence test progress

source/orm/sql/dialect.cpp

@@ -243,6 +243,10 @@ const std::string& dialect::nextval() const {
   return token_at(dialect_token::NextVal);
 }
 
+const std::string& dialect::currval() const {
+  return token_at(dialect_token::CurrVal);
+}
+
 const std::string &dialect::not_() const {
   return token_at(dialect_token::Not);
 }

source/orm/sql/error_code.cpp

@@ -30,6 +30,8 @@ std::string sql_category_impl::message(const int ev) const {
       return "Table exists failed";
     case error_code::RETRIEVE_DATA_FAILED:
       return "Retrieve data failed";
+    case error_code::SEQUENCE_EXISTS_FAILED:
+      return "Sequence exists failed";
     case error_code::RESET_FAILED:
       return "Reset failed";
     case error_code::OPEN_ERROR: