Question

I have a list with some items, & a loop in which I check whether each item in the list is found in the database or not (To insert it if it’s not found).

function AddItems(tx)
    {
        for(var i = 0 ; i<itemscounter; i++)
        { 
            itemI=itemsList[i]; 
            tx.executeSql('SELECT * FROM Items Where ItemsTable.ItemId="'+itemI+'"', [], AddItemsToDB, errorCB);
        }
    }

The problem is that the function waits till it finishes all the iterations then execute the sqlite statement so the itemI value is always equal to itemsList[itemscounter].
So it enters the AddItemsToDB “items counter” times, but always with the same value (the last one in the array).

This is the success Function:

function AddItemsToDB(tx, results)
{
        var len = results.rows.length;
        alert(itemI); // Always has the same value!
        if(len==0)
        {
            tx.executeSql('INSERT INTO ItemsTable (ItemId) VALUES ('+itemI +')');


        }
}

So, I’m wondering if there is some method to pass parameters at the success function itself, or if there is another method to pass the items one by one ?

Answer 1

Yes , there is.Try something like this:

tx.executeSql('SELECT * FROM Items Where ItemsTable.ItemId="'+itemI+'"', [], 
       (function(itemI){
           return function(tx,results){
               AddItemsToDB(tx,results,itemI);
           };
       })(itemI), errorCB);

And modify AddItemsToDB like a:

function AddItemsToDB(tx, results, itemI) {