It errors out when the record couldn't be found Cannot read property 'id' of undefined
How can I keep it from crashing out and handle "undefined"?
let blacklisted = false;
let conStr = "SELECT * FROM `blacklist` WHERE `id` = '"+message.author.id+"'";
con.query(conStr, function(error, result, field) {
console.log(result[0].id);
if(result[0].id){
console.log("Van")
blacklisted = false;
}
});
if (message.author.id !== "397487086522990602" && blacklisted){/*Actual Code*/}
I believe you should add proper checks. Try catch is basically for connection/ query execution related failure not for if data not returned.
So just add check if result[0] exists.
Hence folowing code should serve your purpose:
let blacklisted = false;
let conStr = "SELECT * FROM `blacklist` WHERE `id` = '"+message.author.id+"'";
con.query(conStr, function(error, result, field) {
if(result[0] && result[0].id){ // add check for result[0]
console.log("Van")
blacklisted = false;
}
});
if (message.author.id !== "397487086522990602" && blacklisted){/*Actual Code*/}
Related
Please see the code herein under:
function binanceOrderBook() {
try {
muteHttpExceptions = true;
var workSpreadsheet = SpreadsheetApp.getActiveSpreadsheet();
var mySheet = workSpreadsheet.getSheetByName('Order Books');
if(mySheet == 'Sheet'){
mySheet.activate();
} else {
mySheet = workSpreadsheet.insertSheet('Order Books', 1).activate();
}
var ui = SpreadsheetApp.getUi();
var string = 'https://api.binance.com/api/v3/depth?';
var symbolResponse = ui.prompt('Pair Name', 'Please enter the pair symbol.\n\nExamples: BTCUSDT or ETHBTC:', ui.ButtonSet.OK_CANCEL);
var symbolButton = symbolResponse.getSelectedButton();
if(symbolButton == ui.Button.CANCEL){return}
var mySymbol = symbolResponse.getResponseText();
mySymbol = mySymbol.toUpperCase();
string = string + "symbol=" + mySymbol;
var limitResponse = ui.prompt('Limit:', 'Please enter Limit (Period Quantity).\nValid limits are:5, 10, 20, 50, 100, 500, 1000. \n Default limit is 100.\n You can leave it blank and simply click OK.', ui.ButtonSet.OK_CANCEL);
if(limitResponse.getSelectedButton() == ui.Button.CANCEL){return}
var myLimit = Number(limitResponse.getResponseText());
if(myLimit != 5 && myLimit != 10 && myLimit != 20 && myLimit != 50 && myLimit != 100 && myLimit != 500 && myLimit != 1000){myLimit = 100;}
string = string + "&limit=" + myLimit;
var myDate = new Date().toUTCString();
var jsonOrderBookData = JSON.parse(UrlFetchApp.fetch('https://api.binance.com/api/v3/depth?symbol=' + mySymbol + '&limit=' + myLimit));
reporter(jsonOrderBookData);
} catch (e){
exceptionHandler(e)
}
}
The problem I have is to run UrlFetchApp.fetch again when it encounters an error. I need to run it several times to get the result. So, I need to prevent the script from stopping when an error (code -1003) occurs, but how can I do that?
EDIT: There is a function windows.onerror in javascript which can be set to prevent the program from stopping. Is it useable in GAS? if yes, how? if No, is there a similar solution for GAS?
You could call binanceOrderBook() from within your catch statement. E.g.
...
} catch (e){
binanceOrderBook()
exceptionHandler(e)
}
Of course you probably should have some condition that exits the function if a certain error occurs, or if you know that the function needs to run no more than x number of times you could check that it has run less than x times before executing. For example,
const maxValue = 10 // whatever the max number of executions should be
function binanceOrderBook(executions) {
if (executions >= maxValue) return;
try {
...
} catch(e) {
binanceOrderBook((executions || 0) + 1));
exceptionHandler(e); // note that I am including this here because it's in your original example, but as it is written now, exception handler won't be called until binanceOrderBook executes without an error.
}
}
[Edit] To answer your second question, there is no equivalent to window.onerror that I know of in GAS. However, window.onerror is a global event handler and so would affect errors thrown by any functions defined in your project. To address a concern with a single function call like this, you are better off using a try catch statement as you have.
I am using express and npm mysql (Link)
I want to do a call using
query('SELECT * FROM TABLE WHERE ?', where, cb)
where is a javascript object f.e. : {col1: 'one', col2: 'two'}
But it seems that this doesn't work. It works for SET though to update multiple columns at once.
I want a general method where I can send a different combination of columns to search. I was wondering if there is a built in method to do this.
Meanwhile, I created this script:
var andQuery = "";
var andParams = [];
var isFirst = true;
for (var filter in where) {
if (where.hasOwnProperty(filter)) {
if(!isFirst) {
andQuery += " AND ? ";
} else {
andQuery += " ? ";
isFirst = false;
}
andParams.push({[filter]: where[filter]});
}
}
db.query(
'SELECT * FROM `Table` WHERE ' + andQuery, andParams, (err, results) => {
I am trying to read values from a MySql database and check whether the id that needs to be updated, already exists in database or not. I have been able to make everything else in the program work except the part of checking database. Here is some of my code:
public void updateStatement() throws SQLException{
try
{
connnectDatabse();
}
catch (ClassNotFoundException e)
{
System.out.println("Could not connect to database..");
}
System.out.println("How many entries would you like to update?");
kb=new Scanner(System.in);
int numEntries = kb.nextInt();
int counter =0;
String newName=null, newDepartment =null;
int newSalary=0, newId =0;
int counterValues =0;
while(counterValues != numEntries){
System.out.println("Please enter 5 to view current entries in database\n");
selectStatement();
int idToUpdate =0;
boolean idVerify =false;
//Check if the user id exists in database or not
while(!(idVerify)){
System.out.println("\nPlease enter the ID of the record to update");
idToUpdate = kb.nextInt();
idFoundInDatabase(idArrayList, idToUpdate);
}
System.out.println("Please choose the number of column to update from below options.\n1.ID\n2.Name\n3.Salary\n4.Department");
int columnToUpdate = kb.nextInt();
switch(columnToUpdate){
case 1:
System.out.println("What will be the new id value for the selected ID?");
newId = kb.nextInt();
query = "update employee set ID = ? where ID = ?";
break;
case 2:
System.out.println("What will be the new name for the selected ID?");
newName = kb.next();
query = "update employee set Name = ? where ID = ?";
break;
case 3:
System.out.println("What will be the new salary for the selected ID?");
newSalary = kb.nextInt();
query = "update employee set Salary = ? where ID = ?";
break;
case 4:
System.out.println("What will be the new department for the selected ID?");
newDepartment = kb.next();
query = "update employee set Department = ? where ID = ?";
break;
default:
System.out.println("Correct option not chosen");
}
PreparedStatement st = conn.prepareStatement(query);
if(columnToUpdate ==1){
st.setInt(1, newId);
st.setInt(2, idToUpdate);
}
else if(columnToUpdate ==2){
st.setString(1, newName);
st.setInt(2, idToUpdate);
}
else if(columnToUpdate ==3){
st.setInt(1, newSalary);
st.setInt(2, idToUpdate);
}
else{
st.setString(1, newDepartment);
st.setInt(2, idToUpdate);
}
//execute the prepared statement
st.executeUpdate();
System.out.println("Record successfully updated..");
counterValues++;
}
}
//Code that I am unable to exit. This is
a separate method outside of updateStatement() method.
ArrayList contains the list of ids that are already in the database. ArrayList has been populated successfully.
public boolean idFoundInDatabase(ArrayList<String> arrayList, int id){
boolean validId = false;
while(validId == true){
String idRead = String.valueOf(id);
for (int i=0; i<arrayList.size(); i++){
String elementRead =arrayList.get(i);
if(elementRead.equals(idRead)){
validId = true;
break;
}
else{
validId= false;
}
}
}
return validId;
}
}
If required I am also posting the lines of code where I get the result set to make the array list of ids.
while(result.next()){
String id =result.getString("ID");
idArrayList.add(id);
if(choice == 1 || choice == 2 || choice == 3 || choice == 4){
resultIs = result.getString(columnName);
System.out.println(resultIs);
}
else{
System.out.println(result.getString("ID")+"\t"+result.getString("Name")+
"\t"+result.getString("Salary")+"\t"+result.getString("Department") );
}
}
Problem is exiting the above idFoundInDatabase method. It identifies if the id which user wants to update is in the database or not. On finding even the correct id which exists in the database, it just keeps on reading the values in array list, instead of going to return statement. Am I also doing something wrong where I call this method? Any help will be appreciated. Have been stuck on it for almost a day now. Have done debugging many many times. I am doing this just to get acquainted with jdbc and parameterized queries, so that I can follow the similar thing in a bigger project.Any help is appreciated. Thank You.
A few things:
Your while loop inside of idFoundInDatabase() is not necessary - one simple iteration through the for loop over arrayList is enough.
You are returning a boolean value from that function, but your calling method does not capture and use it, so idVerify is never being changed from false to true, so your input loop repeats forever.
All you need to do sort that out is change idFoundInDatabase(idArrayList, idToUpdate); to idVerify = idFoundInDatabase(idArrayList, idToUpdate); and then your input loop should successfully terminate when a valid id is found.
I'm writing a sort of interface between a TCP Chat server and an SQL Server, and while working on a part where a user submits a value and is assigned a named pulled from a row in this DB with this value. When querying this DB with a value from a telnet shell, I can't get any results from the DB. But I can when I perform the same query in adminer/MySQL # BASH etc...
My thoughts are that it has come down to an encoding issue. Being rather noobish to node, I don't really know what to do. I do have a pretty good experience with JavaScript, just not node.
Code
function setCliNameOrKick(client, key){
key = String(key).replace(/\n\r\b\\\s/gi, "");
var q = "SELECT username FROM webusers WHERE lic = \'"+String(key).toString()+"\'; --";
console.log(key);
query(q);
cli.query(q, function cb(e, r, f){
if(client != null){
console.log(r);
if(r.length >= 1){
client.name = r['username'];
}else{
client.stream.end();
}
}else{
console.log("Was Passed A Null Client!");
}
});
}
That comes from the DB query tool
It takes input from a string sent by the client on connect, alongside an object representing the client
stream.addListener("data", function(data){
if(client.name == null){
data = String(data).replace(new RegExp("[\n]+", "g"), "");
cNameBuff = cNameBuff + data;
if(cNameBuff.length > 1){ //Min Length
//client.name = cNameB;
db.set(client, cNameBuff);
onAuth(client);
}
return;
}
data = String(data);
if(data.length >= 2){
srv.procChat(client, data);
}
});
I have an initial selection which I place into list. I use the list to loop through each record and where it meets certain criteria I run trough a series of inserts, deletes and updates. Finally call the SaveChanges() method to commit changes.
The code runs through without raising an exception but no changes reflect in the database. I have been searching the web with no luck.
I'm using VS2008 with SQL2008 backend.
Please help?
using (SMSEntities db = new SMSEntities())
{
try
{
//Get SMS's to send from Inbox
List<Inbox> tmpInbox = (from c in db.Inboxes where c.Status != "NEW" && c.Status != "SUCCESS" select c).ToList();// new { Inbox.InboxID, Inbox.StatusTrackingID, Inbox.Status, Inbox.NoOfAttempts, Inbox.CellNo, Inbox.SourceCellNo, Inbox.Header, Inbox.Message, Inbox.MessageDate, Inbox.AccountID, Inbox.LastAttemptDate }).ToList();
foreach (Inbox tmpInboxIndex in tmpInbox)
{
bool success = false;
//Check status here
string SentStatus = CheckSMSSentToProvider(tmpInboxIndex.StatusTrackingID);
// Define a transaction scope for the operations.
using (TransactionScope transaction = new TransactionScope())
{
try
{
if ((SentStatus == "DELIVERED") || (SentStatus == "NOTFOUND") || (SentStatus == "DELETED") || (SentStatus == "REJECTED") || (SentStatus == "UNDELIVERED"))
{
//Insert the Log row
Log newLog = new Log();
newLog.InboxID = tmpInboxIndex.InboxID;
newLog.CellNo = tmpInboxIndex.CellNo;
newLog.SourceCellNo = tmpInboxIndex.SourceCellNo;
newLog.Message = tmpInboxIndex.Message;
newLog.Header = tmpInboxIndex.Header;
newLog.MessageDate = tmpInboxIndex.MessageDate;
newLog.AccountID = tmpInboxIndex.AccountID;
newLog.ProcessedDate = DateTime.Now;
newLog.Status = tmpInboxIndex.Status;
newLog.StatusTrackingID = tmpInboxIndex.StatusTrackingID;
newLog.NoOfAttempts = tmpInboxIndex.NoOfAttempts;
newLog.LastAttemptDate = tmpInboxIndex.LastAttemptDate;
db.Logs.AddObject(newLog);
//Delete the Inbox row
if (tmpInbox != null)
{
var deleteInbox = (from c in db.Inboxes where c.InboxID == tmpInboxIndex.InboxID select c).FirstOrDefault();
if (deleteInbox != null)
{
db.DeleteObject(deleteInbox);
//db.SaveChanges(SaveOptions.DetectChangesBeforeSave);
}
}
}
else
{
//Update inbox status
var tmpUpdateInbox = (from c in db.Inboxes where c.InboxID == tmpInboxIndex.InboxID select c).FirstOrDefault();
tmpUpdateInbox.Status = SentStatus;
tmpUpdateInbox.NoOfAttempts = tmpInboxIndex.NoOfAttempts + 1;
tmpUpdateInbox.LastAttemptDate = DateTime.Now;
//db.SaveChanges(SaveOptions.DetectChangesBeforeSave);
}
// Mark the transaction as complete.
transaction.Complete();
success = true;
//break;
}
catch (Exception ex)
{
// Handle errors and deadlocks here and retry if needed.
// Allow an UpdateException to pass through and
// retry, otherwise stop the execution.
if (ex.GetType() != typeof(UpdateException))
{
Console.WriteLine("An error occured. "
+ "The operation cannot be retried."
+ ex.Message);
break;
}
// If we get to this point, the operation will be retried.
}
}
if (success)
{
// Reset the context since the operation succeeded.
//db.AcceptAllChanges();
db.SaveChanges();
}
}
// Dispose the object context.
db.Dispose();
}
catch (Exception exp)
{
throw new Exception("ERROR - " + exp.Message.ToString(), exp);
}
}
return true;
Regards,
GPR.
Are you using a local database file? You may be looking for changes in the wrong place. By default, when the program starts, VS copies the database file into the debug or release folder. Then the program runs and changes are made, and saved, to the file in the debug or release folder. The program ends, and when you look at the database in your source folder it looks the same. You can change the connection string in the app.config to use an absolute path to avoid this.
See http://blogs.msdn.com/b/smartclientdata/archive/2005/08/26/456886.aspx for more info
The TransactionScope is useless if you do not put the call to SaveChanges into it.
Either move the call to SaveChanges into it or remove the TransactionScope completely.