im currently writing a electron App. I wanted to use a SQLite Datebase to store some data. I got a Code like this:
var startTime = performance.now()
let sql = `UPDATE entry
SET
title = "someData",
url = "someData",
username = "someData",
password = "someData",
email = "someData",
note = "someData",
dateOfLastModification = "someData"
WHERE id=someId;`;
this.database.run(sql, (err, data) => {
if (err) {
console.log(err);
} else {
var endTime = performance.now()
console.log(`Call to updateEntry took ${endTime - startTime} milliseconds`)
}
});
Every time i call this code it, it needs more than 200ms. Isnt this too long for such a easy Query? I got other Queries that need nearly the same time. So if i got a behavior in my app that executes three Queries the user have to wait nearly 1 sec.
Any tips what im doing wrong?
Related
I have a problem with my code, I wrote simple flutter app which is f note app, and I have included SQLite as a database , I run the app at first via the emulator and everything went cool , but when I tried to run it on my real device (which is an android device), the database did not respond (i.e I could not add new notes to the database ) and when I went back to run my app via the emulator .. the app did the same thing I found in my real device and in console I found this error
Error: Can't use 'SqfliteDatabaseException' because it is declared more than once.
I need help Please
I saw your code and the problem is that the exception you get is probably related to this one:
PlatformException(sqlite_error, UNIQUE constraint failed: Notetable.id
And it's because you need to manage the unicity of your primary key when you insert a new row. You can have a look at this SO question for a quick reference.
So just to quickly make your code working I've made this changes (please take this code only for reference, write a better one):
void createDataBase(Database db,int newVersion) async{
await db.execute('CREATE TABLE IF NOT EXISTS $noteTable ($col_id INTEGER PRIMARY KEY ,'+
'$col_title TEXT , $col_description TEXT , $col_date TEXT,$col_priority INTEGER)');
}
And
Future<int> insertData(myNote note)async{
var mdatabase = await database;
var _newNoteMap = note.convertToMap();
_newNoteMap['id'] = null;
var result = await mdatabase.insert(noteTable, _newNoteMap);
return result;
}
Pay attention that you always call a DB insert even when you update an existing note.
UPDATE: added additional modification (not listed before)
in databaseObject.dart
Map<String,dynamic> convertToMap(){
var mapObject = Map<String,dynamic>();
mapObject["id"] = _id;
mapObject["title"] = _title;
mapObject["description"] = _description;
mapObject["date"] = _date;
mapObject["priority"] = _priority;
return mapObject;
}
in Note.dart
if(res >= 1){
showAlertDialog('Status', "New note added successfully and the value of result is $res");
}
I'm sure I'm doing something wrong... but every time I query on a calculated datasource, I get the error "cannot handle returning cyclic object."
Here's the gist:
I have a calculated model that fetches a user's google contacts and places the full name field into a table on the UI. The goal is to have a separate text box that can be used to search the full name field and then repopulate the table on the same page with the results of the search, similar to how google contacts search behavior works. The on value change event of the text box sends the textbox value to this server script:
function searchContacts (sq) {
var ds = app.models.Contacts.newQuery();
ds.filters.FullName._contains = sq;
var results = ds.run();
return results;
}
But every time I get the cyclic object error when the values are returned from that function. The error actually fires when the query run command (ds.run) is executed.
I've tried querying the datasource as well, but I've read somewhere that you can't query the datasource of a calculated model because it doesn't exist, so you have to query the model.
Any help would be much appreciated.
From your question it is not 100% clear, what you are trying to do. In case you are actually using Calculated Model, then your Server Script Query should look like this:
var sq = query.parameters.SearchQuery;
var contactsQuery = app.models.Contacts.newQuery();
contactsQuery.filters.FullName._contains = sq;
var contacts = ds.run();
var results = contacts.map(function(contact) {
var calcRecord = app.MyCalcModel.newRecord();
calcRecord.Name = contact.FullName;
return calcRecord;
});
return results;
Note, that you cannot return objects of arbitrary type from Server Script Query, only of type of this particular Calculated Model.
But from some parts of your description and error text if feels like you are trying to load records with async serever call using google.scritp.run. In this case you cannot return App Maker records(App Script doesn't allow this) and you need to map them to simple JSON objects.
I don't think I was super-clear on my original post.
I have a calculated model that is all of the user's contacts from Google Contacts (full name, email, mobile, etc...) On the UI I have a list widget that's populated with all of the Full Name fields and above the list widget a text input that's used to search the list widget. So the search text box's on input change event sends a request to query the Full Names, similar to how Google Contact's search feature works.
Screen Shot
It appears that App Maker doesn't let you query calculated models, so I have this workaround - unless someone comes up with something better:
This is the onInputChange handler for the search text box:
sq = app.pages.SelectClient.descendants.TextBox1.value;
app.datasources.SearchContacts.query.parameters.Name = sq;
app.datasources.SearchContacts.load();
This is the Server Script Code (thanks to #Pavel Shkleinik for the heads up):
var sq = query.parameters.Name;
if (sq !== null) {
return getContactsbyName(sq);
} else {
return getContacts();
}
And the server code with no query:
function getContacts() {
var results = [];
var contacts = ContactsApp.getContacts();
contacts.forEach(function(item) {
var contact = app.models.Contacts.newRecord();
contact.FullName = item.getFullName();
var emails = item.getEmails(ContactsApp.Field.WORK_EMAIL);
if (emails.length > 0) {
contact.PrimaryEmail = emails[0].getAddress();
}
contact.LastName = item.getFamilyName();
contact.FirstName = item.getGivenName();
var phones = item.getPhones(ContactsApp.Field.MOBILE_PHONE);
if (phones.length > 0) {
contact.Mobile = phones[0].getPhoneNumber();
}
var addresses = item.getAddresses(ContactsApp.Field.WORK_ADDRESS);
if (addresses.length > 0) {
contact.Address = addresses[0].getAddress();
}
results.push(contact);
results.sort();
});
return results;
}
And with the query:
function getContactsbyName(sq) {
var results = [];
var contacts = ContactsApp.getContactsByName(sq);
contacts.forEach(function(item) {
var contact = app.models.Contacts.newRecord();
contact.FullName = item.getFullName();
var emails = item.getEmails(ContactsApp.Field.WORK_EMAIL);
if (emails.length > 0) {
contact.PrimaryEmail = emails[0].getAddress();
}
contact.LastName = item.getFamilyName();
contact.FirstName = item.getGivenName();
var phones = item.getPhones(ContactsApp.Field.MOBILE_PHONE);
if (phones.length > 0) {
contact.Mobile = phones[0].getPhoneNumber();
}
var addresses = item.getAddresses(ContactsApp.Field.WORK_ADDRESS);
if (addresses.length > 0) {
contact.Address = addresses[0].getAddress();
}
results.push(contact);
results.sort();
});
return results;
}
This way, the list populates with all of the names when there's no search query present, and then re-populates with the search query results as needed.
The only issue is that the call to the Google Contacts App to populate the Calculated Model is sometimes very slow.
I need help with trying to understand how to delete all data from a table and then try to automatically import a new sheet with data into the newly cleared down table.
I'm currently trying the unload() method client side but that doesn't seem to cleardown my tables
function ClearDown(){
app.datasources.P11d.unload(function(){});
console.log('Finish Delete');
}
I've also tried to create a server side function, which also doesn't appear to work
function ClearTable(){
var records = app.models.P11d.newQuery();
// records.run();
console.log('Server Function Ran');
app.deleteRecords(records.run());
}
This is ran from a client side function:
function Delete(){
google.script.run.withSuccessHandler(function(result){
}).ClearTable();
console.log('Function Ran');
}
Again this is all to no avail
With the import side I've tried to do the below:-
Client Side:
function ImportData(){
console.log('Begin');
var ss = SpreadsheetApp.openById('SHEET ID');
var values = ss.getSheetByName('P11d').getDataRange().getValues();
var ssData = [];
// app.datasources.P11d.unload(function(){});
for (var i = 0; i<values.length; i++){
var newRecord = app.models.P11d.newRecord();
// add all fields to the new record
newRecord.Reg_Number = values[i][0];
newRecord.Reg_Date = values[i][1];
newRecord.Model_Description = values[i][2];
newRecord.P11d_Value = values[i][3];
newRecord.EngineSize = values[i][4];
newRecord.Fuel = values[i][5];
newRecord.CO2 = values[i][6];
newRecord.SIPP = values[i][7];
newRecord.GTA_Code = values[i][8];
newRecord.Type = values[i][9];
ssData.push(newRecord);
// console.log(newRecord.MODEL_FIELD);
}
console.log('Finished');
// return the array of the model.newRecord objects that would be consumed by the Model query.
}
Please can someone help with this, at the moment the way the data is sent over to me adding new stuff into the Drive Table is causing many duplicates.
Thanks in advance,
You can delete all records, import, and read from a spreadsheet using the AMU Library
Copy and paste the server and client scripts into your app.
I'm sure that will make it much easier!
To delete all the data in a model using this:
Button onClick:
google.script.run.AMU.deleteAllData('ModelName');
The correct way to delete records on the server is:
app.models.MODEL_NAME.deleteRecords(key_array);
datasource.unload() simply unloads the widget on the client. It does not affect the database records.
A better way to write your records query on the server is:
var query = app.models.MODEL_NAME.newQuery();
query.filters.your_filter_here;
var records = query.run();
Note that you cannot return a single record or an array of records from anything but a calculated model function without using a function posted here. (You can return a single field of a record using stringify for any json data.)
I am currently working on a solution to create datasource independent tables needed in App Maker.
For the delete function on the server try to change your code just a little bit, this function at least used to work for me, however I have not needed to use it in some time.
function ClearTable(){
var records = app.models.P11d.newQuery().run();
console.log('Server Function Ran');
app.deleteRecords(records);
}
i tried to retrieve data from firebase with angular2 today without success, i can console log data and see object, but for reusing them i have undefined in the console, maybe an issue with synchronous and asynchronous data, what kind of solution i have to retrieve these data with angular2?
thank you
read(){
this.publicationUrl = "https://FBURL/publication";
this.PublicationRef = new Firebase(this.publicationUrl);
this.PublicationRef.on("child_added", function(snapshot){
this.publication = snapshot.val();
console.log(this.publication)
})
}
The issue is that you set data to the wrong this object. Use arrow function to preserve lexical scope:
read() {
this.publicationUrl = "https://FBURL/publication";
this.PublicationRef = new Firebase(this.publicationUrl);
this.PublicationRef.on("child_added", snapshot => {
this.publication = snapshot.val();
console.log(this.publication);
});
}
So i am using the sql.js library i.e. the port of sqlite in javascript which can be found here https://github.com/kripken/sql.js.
This is my code to open and read the database that comes from a flat file store locally.
First the file a local file is selected via this HTML
<input type="file" id="input" onchange="handleFiles(this.files)">
The js code behind the scenes is as follows,
function handleFiles(files) {
var file = files[0];
var reader = new FileReader();
reader.readAsBinaryString(file);
openDbOnFileLoad(reader);
function openDbOnFileLoad(reader){
setTimeout(function () {
if(reader.readyState == reader.DONE) {
//console.log(reader.result);
db = SQL.open(bin2Array(reader.result));
execute("SELECT * FROM table");
} else {
//console.log("Waiting for loading...");
openDbOnFileLoad(reader);
}
}, 500);
}
}
function execute(commands) {
commands = commands.replace(/\n/g, '; ');
try {
var data = db.exec(commands);
console.log(data);
} catch(e) {
console.log(e);
}
}
function bin2Array(bin) {
'use strict';
var i, size = bin.length, ary = [];
for (i = 0; i < size; i++) {
ary.push(bin.charCodeAt(i) & 0xFF);
}
return ary;
}
Now this works and i can access all the columns and values in the database, however there is one column which is of type blob and that just shows up as empty. Any ideas of how i can access the contents of this blob?
The correct answer!
So what I was trying to ask in this question is simply how to read the contents of a column of type blob using sql.js. The correct answer is to specify the column names in the question and for the column that contains data of type blob, get its contents using the hex function i.e. select column1,hex(column2) from table. It was by no means a question about the most efficient way of doing this. I have also written a blog post about this.
Here is a slightly modified copy of the function responsible for initializing my sqlite database:
sqlite.prototype._initQueryDb = function(file, callback) {
self = this;
var reader = new FileReader();
// Fires when the file blob is done loading to memory.
reader.onload = function(event) {
var arrayBuffer = event.target.result,
eightBitArray = new Uint8Array(arrayBuffer),
database = SQL.open(eightBitArray);
self._queryDb = database;
// Trigger the callback to the calling function
callback();
}
// Start reading the file blob.
reader.readAsArrayBuffer(file);
}
In this case, file is a local sqlite database handle that I get from an HTML input element. I specify a function to call when a change event happens to that input and get the blob from the resulting event.target.files[0] object.
For the sake of brevity on my part I left some things out but I can throw together a smaller and more simplified example if you are still struggling.
The answer is: with kripken's sql.js, that you mentioned above you can't. At least as of today (may 2014). The original author doesn't maintain sql.js anymore.
However, I'm the author of a fork of sql.js, that is available here: https://github.com/lovasoa/sql.js .
This fork brings several improvements, including support for prepared statements, in which, contrarily to the original version, values are handled in their natural javascript type, and not only as strings.
With this version, you can handle BLOBs (both for reading and writing), they appear as Uint8Arrays (that you can for instance convert to object URL to display contents to your users).
Here is an example of how to read blob data from a database:
var db = new SQL.Database(eightBitArray); // eightBitArray can be an Uint8Array
var stmt = db.prepare("SELECT blob_column FROM your_table");
while (stmt.step()) { // Executed once for every row of result
var my_blob = stmt.get()[0]; // Get the first column of result
//my_blob is now an Uint8Array, do whatever you want with it
}
db.close(); // Free the memory used by the database
You can see the full documentation here: http://lovasoa.github.io/sql.js/documentation/