How to access a RowDataPacket object

Question

I'm currently developing a desktop application with Node-webkit. During that process I need to get some data from a local MySQL-database.

The querying works fine, but I can't figure out how to access the results. I store all of them in an array that is then passed to a function. In the console they look like this:

RowDataPacket {user_id: 101, ActionsPerformed: 20}
RowDataPacket {user_id: 102, ActionsPerformed: 110}
RowDataPacket {user_id: 104, ActionsPerformed: 3}

And here is the query structure:

var ret = [];
conn.query(SQLquery, function(err, rows, fields) {
    if (err)
        alert("...");
    else {
        for (var i of rows) 
            ret.push(i);
    }
    doStuffwithTheResult(ret);
}

How do I retrieve this in the doStuffwithTheResult function? The values are more important, but if I could get the keys as well that would be great.

Answer 1

Turns out they are normal objects and you can access them through user_id.

RowDataPacket is actually the name of the constructor function that creates an object, it would look like this new RowDataPacket(user_id, ...). You can check by accessing its name [0].constructor.name

If the result is an array, you would have to use [0].user_id.

Answer 2

With Object.prototype approach, JSON.parse(JSON.stringify(rows)) returns object, extract values with Object.values()

let result = Object.values(JSON.parse(JSON.stringify(rows)));

Usage:

result.forEach((v) => console.log(v));

Answer 3

I also met the same problem recently, when I use waterline in express project for complex queries ,use the SQL statement to query.

this is my solution: first transform the return value(RowDataPacket object) into string, and then convert this string into the json object.

The following is code :

//select all user (查询全部用户)
find: function(req, res, next){
    console.log("i am in user find list");
    var sql="select * from tb_user";

    req.models.tb_user.query(sql,function(err, results) {
        console.log('>> results: ', results );
        var string=JSON.stringify(results);
        console.log('>> string: ', string );
        var json =  JSON.parse(string);
        console.log('>> json: ', json);
        console.log('>> user.name: ', json[0].name);
        req.list = json;
        next();
    });
}

The following is console:

    >> results:  [ RowDataPacket {
    user_id: '2fc48bd0-a62c-11e5-9a32-a31e4e4cd6a5',
    name: 'wuwanyu',
    psw: '123',
    school: 'Northeastern university',                                                                                                                                           
    major: 'Communication engineering',                                                                                                                                            
    points: '10',
    datems: '1450514441486',
    createdAt: Sat Dec 19 2015 16:42:31 GMT+0800 (中国标准时间),                                                                                                  
    updatedAt: Sat Dec 19 2015 16:42:31 GMT+0800 (中国标准时间),                                                                                                  
    ID: 3,
    phone: 2147483647 } ]
>> string:  [{"user_id":"2fc48bd0-a62c-11e5-9a32-a31e4e4cd6a5","name":"wuwanyu","psw":"123","school":"Northeastern university","major":"Communication engineering","points":"10","datems":"1450514
441486","createdAt":"2015-12-19T08:42:31.000Z","updatedAt":"2015-12-19T08:42:31.000Z","ID":3,"phone":2147483647}]
>> json:  [ { user_id: '2fc48bd0-a62c-11e5-9a32-a31e4e4cd6a5',
    name: 'wuwanyu',
    psw: '123',
    school: 'Northeastern university',                                                                                                                                           
    major: 'Communication engineering',                                                                                                                                            
    points: '10',
    datems: '1450514441486',
    createdAt: '2015-12-19T08:42:31.000Z',
    updatedAt: '2015-12-19T08:42:31.000Z',
    ID: 3,
    phone: 2147483647 } ]
>> user.name:  wuwanyu