backend tests progress

backends/postgres/src/postgres_connection.cpp

@@ -25,9 +25,10 @@ void postgres_connection::open()
 
   conn_ = PQconnectdb(connection.c_str());
   if (PQstatus(conn_) == CONNECTION_BAD) {
-    const auto msg = PQerrorMessage(conn_);
+    const std::string msg = PQerrorMessage(conn_);
     PQfinish(conn_);
-    throw_postgres_error(msg, "postgres");
+    conn_ = nullptr;
+    throw_postgres_error(msg.c_str(), "postgres");
   }
 }
 

backends/postgres/src/postgres_dialect.cpp

@@ -11,7 +11,7 @@
       return "$" + std::to_string(index);
     })
     .with_token_replace_map({
-                          {dialect::token_t::BEGIN_BINARY_DATA, "E'\\\\"}
+                          {dialect::token_t::BEGIN_BINARY_DATA, "E'\\"}
                           })
     .with_data_type_replace_map({
                                   {data_type_t::type_blob, "BYTEA"}