static String buildInsertSql(String table,String[] fields){
    StringBuilder insert = new StringBuilder(1024);
    insert.append("INSERT INTO ").append(table).append(" (");
    for (int i=0;i<fields.length;i++){
        insert.append(fields[i]);
        if(i<fields.length-1) insert.append(", ");
    }
    insert.append(") VALUES (?, ?, ?)");
    return insert.toString();
}