How to Insert Multiple Rows in a foreach command with LINQ? - linq-to-sql

I wrote these lines:
foreach (var catId in CatIds)
{
AdCategory.AdId = LastAd.AdID;
AdCategory.CategoryId = catId;
EngineDB.Ad_Categories.InsertOnSubmit(AdCategory);
EngineDB.SubmitChanges();
}
and CatIds is an Integer Array.
this command inserts first element correctly but next loop causes this exception:
"Cannot add an entity that already exists."
How can I fix it. please help me as soon as posible!

as Jimmie said you need to create a new AdCategory in the loop. You also probably don't want to call SubmitChanges every time as well, this call uses a transaction to make sure all the items are added at once, or none at all.
Try something like:
foreach (var catId in CatIds)
{
var AdCategory = new AdCategory()
{
AdId = LastAd.AdID,
CategoryId = catId
}
EngineDB.Ad_Categories.InsertOnSubmit(AdCategory);
}
EngineDB.SubmitChanges();

You need to create a new AdCategory in the loop. Otherwise, as the error states, you are tyring to insert the same object again and again.
You should also move
EngineDB.SubmitChanges();
outside of the loop so you only make 1 call to the database.

Related

as3 dynamic variable within a loop

I need to have the screenPage var accessible for later calls. I am dynamically creating several pages. The issue is when I call screenPage.startDrag(); then it only drags the last page. How can I add a var in the name or make all the screenPages accessible through code?
Here is code in short:
var screenPage:MovieClip;
for(var p = 1; daTotalPages >= p; p++)
{
screenPage = new theFlagScreen();
}
Can I make screenPage a dynamic var and add like a 1 at the end and then a 2 and so forth with the loop?
Why not use an array ?
var pages:Array = new Array;
for(var p = 1; daTotalPages >= p; p++)
{
var screenPage:MovieClip = new theFlagScreen();
pages.push(screenPage)
}
Now you have an array containing all of your instances.
var myPage:MovieClip = pages[5] as MovieClip;
myPage.startDrag();
Also, the code you have above is creating an instance each time through, but since you then go ahead and create a new one each iteration and assign it to the same variable without storing it or adding it to the display list.... once you create a new one, the last one is marked for garbage collection.
The result is only the LAST instance you created still exists as it's the only one that has a variable that references it.
screenPage is a reference to just ONE thing. In your loop you keep overwriting it as you go and so you end up with it pointing to the very last instance of theFlagScreen... all the others are now lost.
You should follow prototypical's advice and store these instances in an array, that way you don't lose them.

AS3 stack overflow?

Working with Arrays. I create objects on a Class base, push them into an Array, I have 2 buttons: one adds a Child and pushes it into the Array, second one Shifts Array and removes the Child. Also a function on my mouse, if I click an object, I define it's Array number, remove the Child and... well, not sure if successful but "delete Array[i];" where i is target's Array number. I can see Array.length in a text field every time I do something. Second button actually does remove an object from Array, the number decreases. But deleting a specified object from the Array, as well as Array.slice(i,1), doesn't reduce the Array length. So I'm afraid it may cause overflow. It's only Array, not sure, maybe it's fine to have over a million cells in an Array? Like if I make a game with meteor shower, meteors are removed from the screen, but the Array still has their cells. And if they appear like 30-50 per sec, it's obvious I may get memory problems in 20 minutes of running it. Well it's 60k so maybe I shouldn't worry as only graphics take much memory?
Still, I could use an advice on how to shift an object in a middle of an Array. Chosen one. How do I delete it as if it never was created, same as Shift does? (it does, right?)
Array.splice() will do most of the tricks. As you remove the meteor off screen, you can splice it out of the array, do like this:
var i:int=meteorArray.indexOf(meteorToRemove);
if (i>=0) meteorArray.splice(i,1);
You should not create a new object as a good practice if you are deleting other. Try recycling, or better said 'object pools'
You should figure out the number max of elements you may use at once. create a property 'active' on each and set it to true or false instead of creating/deleting. Then you can run the update on each object and update it only if necessary
For example:
var meteors:Array = [];
// create 500 meteors
for ( var i:int = 0; i < 500; i++ ) {
var meteor:Meteor = new Meteor();
meteor.active = false;
meteors.push(meteor);
}
// enable one meteor
meteors[0].active = true;
// in your update method:
for each (var meteor in meteors )
if ( meteor.active )
meteor.update();
Hope that helps.
Also you can add a helper method to get a meteor available:
function getMeteorAvailable():Meteor
{
for each (var meteor in meteors )
if ( !meteor.active )
return meteor;
}

Splice then re-index array in ActionScript 3

I want to remove the first four indexes from the array using splice(), then rebuild the array starting at index 0. How do I do this?
Array.index[0] = 'one';
Array.index[1] = 'two';
Array.index[2] = 'three';
Array.index[3] = 'four';
Array.index[4] = 'five';
Array.index[5] = 'six';
Array.index[6] = 'seven';
Array.index[7] = 'eight';
Array.splice(0, 4);
Array.index[0] = 'five';
Array.index[1] = 'six';
Array.index[2] = 'seven';
Array.index[3] = 'eight';
I am accessing the array via a timer, on each iteration I want to remove the first four indexes of the array. I assumed splice() would remove the indexes then rebuild the array starting at 0 index. it doesn't, so instead what I have done is created a 'deleteIndex' variable, on each iteration a +4 is added to deleteIndex.
var deleteIndex:int = 4;
function updateTimer(event:TimerEvent):void
{
Array.splice(0,deleteIndex);
deleteIndex = deleteIndex + 4;
}
What type of object is "Array" in the code you have shown? The Flash Array object does not have a property named "index". The Array class is dynamic, which means that it let's you add random properties to it at run time (which seems to be what you are doing).
In any case, if you are using the standard Flash Array class, it's splice() method updates the array indexes automatically. Here is a code example that proves it:
var a:Array = [1,2,3,4,5];
trace("third element: ", a[2]); // output: 3
a.splice(2,1); // delete 3rd element
trace(a); // output: 1,2,4,5
trace(a.length); // ouput: 4
trace("third element: ", a[2]); // output: 4
If I am understanding what you want correctly, you need to use the unshift method of Array.
example :
var someArray:Array = new Array(0,1,2,3,4,5,6,7,8);
someArray.splice(0,4);
somearray.unshift(5,6,7,8);
Also, you are using the Array Class improperly, you need to create an instance of an array to work with first.
The question is confusing because you used Array class name instead of an instance of an array. But as the commenter on this post said, if you splice elements, it automatically re-indexes.
im not sure what you want to do, but Array=Array.splice(0,4) should fix somethin..

Creating a user generated list in flash

I'm trying to create a flash application that will keep track of user generated values. The app should basically allow the user to input the name of the item and it's cost. The total costs should then be added up to show a total value to the user. I can probably figure out how to add the values together, but I'm not really sure how to allow the user to create a list and then allow the user to save it. Can anyone point me towards a tutorial or point me in the right direction?
I am using variables to add user inputed numbers to come up with a total. The first problem is that actionscript 3.0 does not allow variables for texts. I just converted it to 2.0 to fix this. The second problem, is when I test the app and put in my values and click submit, I get NaN in the total values field. Is there a reason why it wouldn't add the values?
Here is the code I used for the submit button:
on (release) {
total = Number(rent) + Number(food) + Number(travel) + Number(entertainment) + Number(bills);
}
Am I missing anything?
Can I give the input text instance names and then give them variables? How are some ways to go about this?
Thanks for the help!
Have an object array, say for example
var stack:Array = new Array();
Then push the item name and it's cost to that array when user inputs, like
stack.push({item:AAA, cost:xx});
So that you can generate the list whenever you want with that array.
You have to see how this works in code. A list in actionscript could be stored inside an array, vector, dictionary or even an Object.
Var myList:Array = [];
myList.push({name: "item 1", cost: 5 });
myList.push({name: "item 2", cost: 7.5 });
If you want to grab the 'product' of "item 1" from the list, you have to create a function for that, lets call it getProductByName
function getProductByName(name:String):Object
{
for each(var product:Object in myList)
{
if (product.name === name) return product;
}
return null; // no match found
}
You can call that function like this:
var product = getProductByName("item 1");
trace(product.cost); // 5
And you can alter the product, so lets make it more expensive
product.cost += 1;
trace(product.cost); // 6
Have fun! If you are using classes, you would create one for the product, with public name and cost, and in that case you'de better use a vector, to ensure working with the right type.
This is what fixed the issue for me in action script 3.0:
myButton.addEventListener(MouseEvent.CLICK, addThem);
function addThem(e:MouseEvent)
{
totalField.text = String ( Number(field1.text) + Number(field2.text) + ....);
}
I also had to name the instances appropriately.

google visualization api, identify tableid in response function

Hmmm, maybe someone can help me out here or point me in the right direction , as i have been banging my head against the wall for a number of days now and dont seem to be gettin anywhere useful.
(and admittedly i'm pretty new with regards to json,objects, google visulization etc)
essentially, i am running 3 different queries on the same page against 3 different fusion tables, which in return are supposed to return an array of 3 different xets of markers.
all is fine, when i run the queries individually and make an array of the markers .
however, running the 3 queries on the same page, i can't seem to find a way to identify the query in the response function.
any hints much appreciated. and i'll be happy to provide more info if needed (tried to get rid of some unneccessary stuff)
this is what i have. thanks
a) calling the function "setFusionData()" with all relevant vars. something like setFusionData("'LatLng','name'", 2729461);
(this is calles 3 times with different variables)
function setFusionData(selColumns,tableId) {
/****
an actual query example is this:
http://www.google.com/fusiontables/gvizdata?tqx=reqId:1234&tq="select+'LatLng','name'+from+2729461"
****/
var query = new google.visualization.Query(
'http://www.google.com/fusiontables/gvizdata?tqx=reqId:1234&tq='+ encodeURIComponent("SELECT "+selColumns+" FROM "+tableId+"")
);
query.send(getFusionData); //do something with the response
}
function getFusionData(response) {
/**
here, is the problem as i need to get the table id or reqId or anything that is uniquely passed on from "setFusionData" above
also something like
alert(JSON.stringify(response)) does not return any reqId or table id either
***/
/*return rows/columns and add values to an array of markers***/
var numRows = response.getDataTable().getNumberOfRows();
var numCols = response.getDataTable().getNumberOfColumns();
for (i = 0; i < numRows; i++) {
/* add markers to array etc this works fine***/
}
}
i also tried something like this:
function setFusionData(selColumns,tableId) {
......
query.send(getFusionData({reqId:tableId}));
}
function getFusionData(response) {
alert(response['reqId']);//returns tableId. but how do i get the tableData ?
}
with wich i can get the reqId, but not the table*Data*. So I am only able to get either id or data :(
----edit----------------
after messing around a bit more (see below) it appears that the key/value pairs that get returned when typing the query into the browser directly are different than what gets returned by the call from the script...i.e the following
http ://www.google.com/fusiontables/gvizdata?tqx=reqId:1234&tq="select+'LatLng','name'+from+2729461"
typed directly into the browser bar will return
version:'0.5',reqId:'1234',status:'ok',table etc
however, calling the same from within the script returns something like
{
"rj":"0.5","ef":"ok","pb":[],"qb":[],"h":"{"cols":
[{"id":"col2","label":"LatLng","type":"string"},{"id":"col1","label":"name","type":"string"}],
"rows":
[{"c":[{"v":"47.20572,12.70414"},
{"v":"Hohe Tauern"}]},{"c":[{"v":"47.5530395,12.925611"},{"v":"Berchtesgaden"}]},{"c":[{"v":"47.5585405,14.61887"},{"v":"Gesu00e4use"}]}],
"p":{"totalrows":3}
}"
}
, so no 'reqId' but only some cryptic keys (without one that looks like the reqId either)...... anyone any idea why that would/could be ?
Sometimes you can figure it out by just looking at the JSON response, your sample request returns:
google.visualization.Query.setResponse({
version:'0.5',
reqId:'1234',
status:'ok',
table: {
...
}
})
You already got response.reqId to identify which request is this the response for, now you can use response.table to create a new DataTable instance:
var dt = new google.visualization.DataTable(response.table);
Or, since you have multiple tables, put then in an array indexed with the reqId
tables[response.reqId] = new google.visualization.DataTable(response.table);
You'd do var tables = new Array() before calling setFusionData() for the first time.