Related
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.
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.
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));
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
Hi try this 100% works:
results=JSON.parse(JSON.stringify(results))
doStuffwithTheResult(results);
You can copy all enumerable own properties of an object to a new one by Object.assign(target, ...sources):
trivial_object = Object.assign({}, non_trivial_object);
so in your scenario, it should be enough to change
ret.push(i);
to
ret.push(Object.assign({}, i));
you try the code which gives JSON without rowdatapacket:
var ret = [];
conn.query(SQLquery, function(err, rows, fields) {
if (err)
alert("...");
else {
ret = JSON.stringify(rows);
}
doStuffwithTheResult(ret);
}
going off of jan's answer of shallow-copying the object, another clean implementation using map function,
High level of what this solution does: iterate through all the rows and copy the rows as valid js objects.
// function will be used on every row returned by the query
const objectifyRawPacket = row => ({...row});
// iterate over all items and convert the raw packet row -> js object
const convertedResponse = results.map(objectifyRawPacket);
We leveraged the array map function: it will go over every item in the array, use the item as input to the function, and insert the output of the function into the array you're assigning.
more specifically on the objectifyRawPacket function: each time it's called its seeing the "{ RawDataPacket }" from the source array. These objects act a lot like normal objects - the "..." (spread) operator copies items from the array after the periods - essentially copying the items into the object it's being called in.
The parens around the spread operator on the function are necessary to implicitly return an object from an arrow function.
Solution
Just do: JSON.stringify(results)
I found an easy way
Object.prototype.parseSqlResult = function () {
return JSON.parse(JSON.stringify(this[0]))
}
At db layer do the parsing as
let users= await util.knex.raw('select * from user')
return users.parseSqlResult()
This will return elements as normal JSON array.
If anybody needs to retrive specific RowDataPacket object from multiple queries, here it is.
Before you start
Important: Ensure you enable multipleStatements in your mysql connection like so:
// Connection to MySQL
var db = mysql.createConnection({
host: 'localhost',
user: 'root',
password: '123',
database: 'TEST',
multipleStatements: true
});
Multiple Queries
Let's say we have multiple queries running:
// All Queries are here
const lastCheckedQuery = `
-- Query 1
SELECT * FROM table1
;
-- Query 2
SELECT * FROM table2;
`
;
// Run the query
db.query(lastCheckedQuery, (error, result) => {
if(error) {
// Show error
return res.status(500).send("Unexpected database error");
}
If we console.log(result) you'll get such output:
[
[
RowDataPacket {
id: 1,
ColumnFromTable1: 'a',
}
],
[
RowDataPacket {
id: 1,
ColumnFromTable2: 'b',
}
]
]
Both results show for both tables.
Here is where basic Javascript array's come in place https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
To get data from table1 and column named ColumnFromTable1 we do
result[0][0].ColumnFromTable1 // Notice the double [0]
which gives us result of a.
db.query('select * from login',(err, results, fields)=>{
if(err){
console.log('error in fetching data')
}
var string=JSON.stringify(results);
console.log(string);
var json = JSON.parse(string);
// to get one value here is the option
console.log(json[0].name);
})
conn.query(sql, (err,res,fields) => {
let rawData = res;
let dataNormalized = {...rawData[0]};
})
//Object Destructuring
This worked for me hope it helps you.
I think it is simplest way to copy object.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment
Simpler way:
.then( resp=> {
let resultFromDb= Object.values(resp)[0]
console.log(resultFromDb)
}
In my example I received an object in response.
When I use Object.values I have the value of the property as a response, however it comes inside an array, using [0] access the first index of this array, now i have the value to use it where I need it.
I had this problem when trying to consume a value returned from a stored procedure.
console.log(result[0]);
would output "[ RowDataPacket { datetime: '2019-11-15 16:37:05' } ]".
I found that
console.log(results[0][0].datetime);
Gave me the value I wanted.
I had a similar problem and the solution was as follows:
const results = pool.query('sql sentence',[params]);
console.log((results[0])[0].name);
How to ACCESS what you get back from the database, this works for me:
async function getPageId(pageSlug){
let sql_update = 'SELECT id FROM pages WHERE pageSlug = ?';
let arrValues = [
pageSlug
];
let result = await mydb.query(sql_update, arrValues);
let r = JSON.parse(JSON.stringify(result));
if(r?.length){
return r[0].id;
}else{
return false;
}
}
I really don't see what is the big deal with this I mean look if a run my sp which is CALL ps_get_roles();.
Yes I get back an ugly ass response from DB and stuff. Which is this one:
[
[
RowDataPacket {
id: 1,
role: 'Admin',
created_at: '2019-12-19 16:03:46'
},
RowDataPacket {
id: 2,
role: 'Recruiter',
created_at: '2019-12-19 16:03:46'
},
RowDataPacket {
id: 3,
role: 'Regular',
created_at: '2019-12-19 16:03:46'
}
],
OkPacket {
fieldCount: 0,
affectedRows: 0,
insertId: 0,
serverStatus: 35,
warningCount: 0,
message: '',
protocol41: true,
changedRows: 0
}
]
it is an array that kind of look like this:
rows[0] = [
RowDataPacket {/* them table rows*/ },
RowDataPacket { },
RowDataPacket { }
];
rows[1] = OkPacket {
/* them props */
}
but if I do an http response to index [0] of rows at the client I get:
[
{"id":1,"role":"Admin","created_at":"2019-12-19 16:03:46"},
{"id":2,"role":"Recruiter","created_at":"2019-12-19 16:03:46"},
{"id":3,"role":"Regular","created_at":"2019-12-19 16:03:46"}
]
and I didnt have to do none of yow things
rows[0].map(row => {
return console.log("row: ", {...row});
});
the output gets some like this:
row: { id: 1, role: 'Admin', created_at: '2019-12-19 16:03:46' }
row: { id: 2, role: 'Recruiter', created_at: '2019-12-19 16:03:46' }
row: { id: 3, role: 'Regular', created_at: '2019-12-19 16:03:46' }
So you all is tripping for no reason. Or it also could be the fact that I'm running store procedures instead of regular querys, the response from query and sp is not the same.
I am trying to make a PUT request for an object that doesn't contain an exact 'id' key. I am using the Angular InMemory Database service. The Object structure is as follows:
{
students: [{
name: 'jim',
age: 10,
grade: 4,
},{
name: 'james',
age: 11,
grade: 5,
}]
}
Service Method
updateStudent(student: Student) {
const url = 'api/students'
const options = { name: student.name };
return this.httpClient.put(url, student, { params: options }).pipe(
tap(_ => console.log('student updated)),
catchError(this.handleError('updating student'))
);
}
Component Method
updateStudent() {
this.studentService.updateStudent(this.selectedStudent).subscribe();
}
Where selectedStudent is:
{
name: 'jim',
age: 12,
grade: 6
}
If I change the PUT to a GET the in memory database come back with the correct student in the array. But with the code stated above I get a 404 Error
I'm trying to use normalizer to normalize some JSON. My JSON looks like
total: 8029,
items: [
{
id: 1,
name: 'Jacket1',
sku: '123',
upc: '1',
price: '99.99',
images: ['url1', 'url2'],
category: 'clothing',
thumbnail:
'https://cdn.zeplin.io/5969021e44c5978909d5278b/assets/1CE5FF07-E70F-4413-85BF-49C08AA559DE.png',
}, ...
and from the examples, I thought this might work
const itemSchema = new schema.Entity('items')
const itemsSchema = new schema.Entity('result', {
items: [itemSchema],
})
const foo = normalize(fakeDatabase, itemsSchema)
But I end up with one result that is undefined, and that undefined value has some funky stuff in it.
What am I doing wrong?
I don't believe itemsSchema is necessary. Try either:
normalize(fakeDatabase, { items: new schema.Array(itemSchema) })
or
normalize(fakeDatabase, { items: [itemSchema] })
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.
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.
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));
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
Hi try this 100% works:
results=JSON.parse(JSON.stringify(results))
doStuffwithTheResult(results);
You can copy all enumerable own properties of an object to a new one by Object.assign(target, ...sources):
trivial_object = Object.assign({}, non_trivial_object);
so in your scenario, it should be enough to change
ret.push(i);
to
ret.push(Object.assign({}, i));
you try the code which gives JSON without rowdatapacket:
var ret = [];
conn.query(SQLquery, function(err, rows, fields) {
if (err)
alert("...");
else {
ret = JSON.stringify(rows);
}
doStuffwithTheResult(ret);
}
going off of jan's answer of shallow-copying the object, another clean implementation using map function,
High level of what this solution does: iterate through all the rows and copy the rows as valid js objects.
// function will be used on every row returned by the query
const objectifyRawPacket = row => ({...row});
// iterate over all items and convert the raw packet row -> js object
const convertedResponse = results.map(objectifyRawPacket);
We leveraged the array map function: it will go over every item in the array, use the item as input to the function, and insert the output of the function into the array you're assigning.
more specifically on the objectifyRawPacket function: each time it's called its seeing the "{ RawDataPacket }" from the source array. These objects act a lot like normal objects - the "..." (spread) operator copies items from the array after the periods - essentially copying the items into the object it's being called in.
The parens around the spread operator on the function are necessary to implicitly return an object from an arrow function.
Solution
Just do: JSON.stringify(results)
I found an easy way
Object.prototype.parseSqlResult = function () {
return JSON.parse(JSON.stringify(this[0]))
}
At db layer do the parsing as
let users= await util.knex.raw('select * from user')
return users.parseSqlResult()
This will return elements as normal JSON array.
If anybody needs to retrive specific RowDataPacket object from multiple queries, here it is.
Before you start
Important: Ensure you enable multipleStatements in your mysql connection like so:
// Connection to MySQL
var db = mysql.createConnection({
host: 'localhost',
user: 'root',
password: '123',
database: 'TEST',
multipleStatements: true
});
Multiple Queries
Let's say we have multiple queries running:
// All Queries are here
const lastCheckedQuery = `
-- Query 1
SELECT * FROM table1
;
-- Query 2
SELECT * FROM table2;
`
;
// Run the query
db.query(lastCheckedQuery, (error, result) => {
if(error) {
// Show error
return res.status(500).send("Unexpected database error");
}
If we console.log(result) you'll get such output:
[
[
RowDataPacket {
id: 1,
ColumnFromTable1: 'a',
}
],
[
RowDataPacket {
id: 1,
ColumnFromTable2: 'b',
}
]
]
Both results show for both tables.
Here is where basic Javascript array's come in place https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
To get data from table1 and column named ColumnFromTable1 we do
result[0][0].ColumnFromTable1 // Notice the double [0]
which gives us result of a.
db.query('select * from login',(err, results, fields)=>{
if(err){
console.log('error in fetching data')
}
var string=JSON.stringify(results);
console.log(string);
var json = JSON.parse(string);
// to get one value here is the option
console.log(json[0].name);
})
conn.query(sql, (err,res,fields) => {
let rawData = res;
let dataNormalized = {...rawData[0]};
})
//Object Destructuring
This worked for me hope it helps you.
I think it is simplest way to copy object.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment
Simpler way:
.then( resp=> {
let resultFromDb= Object.values(resp)[0]
console.log(resultFromDb)
}
In my example I received an object in response.
When I use Object.values I have the value of the property as a response, however it comes inside an array, using [0] access the first index of this array, now i have the value to use it where I need it.
I had this problem when trying to consume a value returned from a stored procedure.
console.log(result[0]);
would output "[ RowDataPacket { datetime: '2019-11-15 16:37:05' } ]".
I found that
console.log(results[0][0].datetime);
Gave me the value I wanted.
I had a similar problem and the solution was as follows:
const results = pool.query('sql sentence',[params]);
console.log((results[0])[0].name);
How to ACCESS what you get back from the database, this works for me:
async function getPageId(pageSlug){
let sql_update = 'SELECT id FROM pages WHERE pageSlug = ?';
let arrValues = [
pageSlug
];
let result = await mydb.query(sql_update, arrValues);
let r = JSON.parse(JSON.stringify(result));
if(r?.length){
return r[0].id;
}else{
return false;
}
}
I really don't see what is the big deal with this I mean look if a run my sp which is CALL ps_get_roles();.
Yes I get back an ugly ass response from DB and stuff. Which is this one:
[
[
RowDataPacket {
id: 1,
role: 'Admin',
created_at: '2019-12-19 16:03:46'
},
RowDataPacket {
id: 2,
role: 'Recruiter',
created_at: '2019-12-19 16:03:46'
},
RowDataPacket {
id: 3,
role: 'Regular',
created_at: '2019-12-19 16:03:46'
}
],
OkPacket {
fieldCount: 0,
affectedRows: 0,
insertId: 0,
serverStatus: 35,
warningCount: 0,
message: '',
protocol41: true,
changedRows: 0
}
]
it is an array that kind of look like this:
rows[0] = [
RowDataPacket {/* them table rows*/ },
RowDataPacket { },
RowDataPacket { }
];
rows[1] = OkPacket {
/* them props */
}
but if I do an http response to index [0] of rows at the client I get:
[
{"id":1,"role":"Admin","created_at":"2019-12-19 16:03:46"},
{"id":2,"role":"Recruiter","created_at":"2019-12-19 16:03:46"},
{"id":3,"role":"Regular","created_at":"2019-12-19 16:03:46"}
]
and I didnt have to do none of yow things
rows[0].map(row => {
return console.log("row: ", {...row});
});
the output gets some like this:
row: { id: 1, role: 'Admin', created_at: '2019-12-19 16:03:46' }
row: { id: 2, role: 'Recruiter', created_at: '2019-12-19 16:03:46' }
row: { id: 3, role: 'Regular', created_at: '2019-12-19 16:03:46' }
So you all is tripping for no reason. Or it also could be the fact that I'm running store procedures instead of regular querys, the response from query and sp is not the same.
I'm looking for a performant way to update selected records in a collection based on the presence of the record's ID in a reference array. For example, given a reference array of [1,2,5] I want each record in the collection with those IDs to be given an attribute of $selected: true. Each record in the collection will be associated with a checkbox in the view and $selected items will be checked (fiddle)
I've started with the approach below (coffeescript) but I'm new to Lodash so I thought I'd ask for some feedback. Also, I'm not sure what the cleanest way is to set $selected: false to the alternate records?
# Whole Collection
collection = [
{id:1, name: "one"},
{id:2, name: "two"},
{id:3, name: "three"},
{id:4, name: "four"},
{id:5, name: "five"}
]
# Mark subset as selected
for id in [1,2,5]
_.where( collection, 'id':id ).forEach( (record) ->
record.$selected = true
)
Here's a fiddle...
http://jsfiddle.net/zd78e4bj/
EDIT
Added reference to two-way binding $selected elements to checkboxes in the view
I would do something like this (sorry it's not CoffeScript, but you get the idea):
var collection = [
{ id:1, name: 'one' },
{ id:2, name: 'two' },
{ id:3, name: 'three' },
{ id:4, name: 'four' },
{ id:5, name: 'five'}
];
var ids = [ 1, 2, 5 ];
_(collection)
.indexBy('id')
.at(ids)
.each(_.ary(_.partialRight(_.assign, { $selected: true }), 1))
.value();
console.log(collection);
// →
// [
// { id: 1, name: 'one', $selected: true },
// { id: 2, name: 'two', $selected: true },
// { id: 3, name: 'three' },
// { id: 4, name: 'four' },
// { id: 5, name: 'five', $selected: true }
// ]
First, we create an intermediary object using indexBy(). The keys are the id values in collection. Next, we pass at() the ids we're interested in. This builds a new collection containing only the ids we're after.
The last step is to use each() to add the $selected property. This is done by combining partialRight(), assign(), and ary(). The partially-applied argument is the new $selected property. We use ary() to make sure the callback passed to each() only has one argument.
You can use the map or forEach function to do all of this either in Lodash or native JavaScript. Map creates a new list and forEach will mutate the existing list.
The key to these is the transformation function. This function will set the $selected to true or false if it exists or not in the ids collection.
function mark(item) {
item['$selected'] = (ids.indexOf(item.id) > -1);
return item;
}
You could build a more generic transformer using:
function markItemByList(list, property, searchField) {
return function(item) {
item[property] = (list.indexOf(item[searchField]) > -1);
return item;
}
}
Coffeescript would be:
markItemByList = (list, property, searchField) ->
(item) ->
item[property] = (list.indexOf(item[searchField])) > -1)
item
If you want a mutable implementation:
function select(ids, collection) {
collection.forEach(markItemByList(ids, '$selected', 'id'));
}
Here's a lodash immutable implementation:
function select(ids, collection) {
return _.map(collection, markItemByList(ids, '$selected', 'id'));
}
Here's a pure JavaScript immutable implementation:
function select(ids, collection) {
return collection.map(markItemByList(ids, '$selected', 'id'));
}
Here's an angular implementation:
angular.forEach(collection, markItemsByList(ids, '$selected', 'id'));