retuns error while update,QSqlQuery::value: not positioned on a valid record

I am trying to update my table "abc" but when my update query is executed it is inserting a new record instead of just updating. My record_id is correct but still it is inserting and giving following log:

QSqlQuery::value: not positioned on a valid record

following code is used to update data

QSqlQuery query;
        qDebug()<<"EditMode"<<m_templateId;
        query.prepare("UPDATE templates SET title = :title,"
                      "qml = :qml, "
                      "json = :json, "
                      "defaulttemplate = :defaulttemplate, "
                      "created = :created, "
                      "createdby = :createdby, "
                      "modified = :modified, "
                      "modifiedby = :modifiedby"
                      " WHERE template_id = :templateID "
                      );
        query.bindValue(":templateID",m_templateId);
        query.bindValue(":title", m_title);
        query.bindValue(":qml", generatedQML());
        query.bindValue(":json", generatedJSON());
        query.bindValue(":defaulttemplate", 0);
        query.bindValue(":created", now);
        query.bindValue(":createdby", AppSettings::user_id());
        query.bindValue(":modified", now);
        query.bindValue(":modifiedby", AppSettings::user_id());

        query.exec();