Error when create column in android sqlite

hi people of stackoverflow.

I have a problem when create column in sqlite data base. the error is that I create column but this not created in database. I realize Debug using logs and before add data base this exist afters this is null

help me please.

add code

public void onCreateDataBase(List<Map<String, Object>> model) {
    String sqlStringT;
    if (model != null) {
        List<Map<String, Object>> fields;
        int cont, totalFields;
        for (Map<String, Object> dataTable : model) {
            fields = (List<Map<String, Object>>) dataTable.get("fields");
            totalFields = fields.size() - 1;
            cont = 0;
            // create the table
            sqlStringT = " CREATE TABLE obj_"
                    + dataTable.get("name") + "( f_pk_id INTEGER PRIMARY KEY autoincrement,";

            for (Map<String, Object> dataAttribute : fields) {
                String commaS = " , ";
                String defaultValue = "" + dataAttribute.get("defaultValue");
                defaultValue = " NULL ";

                if (cont == totalFields) {
                    commaS = "";
                }
                String fieldLenght = "";
                if (dataAttribute.get("length") != null && !dataAttribute.get("length").toString().equals("")) {
                    fieldLenght = "(" + dataAttribute.get("length") + ")";
                }

                String fieldType = dataAttribute.get("fieldType") + "";
                if (fieldType.equals("-")) {
                    fieldType = "varchar";
                }
                sqlStringT += " f_" + dataAttribute.get("fieldName") + " "
                        + fieldType + fieldLenght
                        + " DEFAULT " + defaultValue + " " + commaS;
                fieldType = null;
                cont++;
            }

            sqlStringT += " );  ";
            Log.d(TAG, "string sql for table " + sqlStringT);
            this.dbLocal.execSQL(sqlStringT);

        }
        fields = null;
    }
}