realprice | 實價登錄原始資料備份下載 open data | Web Framework library

New to Ruby. Receiving error:

item_container.rb:14:in add_item': undefined method<' for nil:NilClass (NoMethodError)

I know what this error means but can't understand what caused it and how to fix it? Everything was okay before making ClassMethods, InstanceMethods, and adding callback.

I want to filter out data from a database with few criteria (let's assume it is 8). And below query method do this in a good way. But in fact, this criterias passed to the query method can be null (it means that should not be included to select query).

How I should handle this situation? I really don't want to make n-methods to handle each case - it is not a good way.

I am using about 20 variables which they are created inside a void. So my question is do i need to dispose them after my void will be finish? Or gc will do this automatically? Also should i create them inside void Title or Inside my brackets?

Example:

I have a page based app, using RootViewController, ModelViewController, DataViewController, and a SearchViewController.

In my searchViewController, I search for an item and then add or remove that Item to an array which is contained in a Manager class(and UserDefaults), which the modelViewController uses to instantiate an instance of DataViewController with the correct information loaded using the dataObject. Depending on whether an Item was added or removed, I use a Bool to determine which segue was used, addCoin or removeCoin, so that the RootViewController(PageView) will show either the last page in the array, (when a page is added) or the first (when removed).

Everything was working fine until I ran into an error which I can not diagnose, the problem is that when I add a page, the app crashes, giving me a "unexpectadely found nil when unwrapping an optional value"

This appears to be the problem function, in the searchViewController 'self.performSegue(withIdentifier: "addCoin"' seems to be called instantly, even without the dispatchque:

I am making a currency converter that updates currencies simultaneously as you type. The currencies are held in a tableView and the cell is a custom cell.

I want to be able to type into one cell, and see all the other cells update with the value from the conversion calculation. The calculation works, but I am not sure how to get the data back into the correct cells, as essentially there is only one as it is a reusable cell.

Here is the cell class, (I am just showing the input to keep things clear.):

I would like to know how I can the data attribute of form select using Vue js. Here is the select

So I have this problem, banging my head to the wall for the last several days, where I have a simple form, there might be more than one divs with four inputs but they are all related to each other. What I'm trying to do is to calculate the last input's in a div value which is based on the rest of the inputs' value and are typed dynamically and then to setState() to return a new state. I have handler functions (to add, remove or change value of input fields) which work when I don't need to handle this particular update. Now here's the code:

I have 2 columns: price and dec. As shown in this sample dataframe:

I'm using a a multiple query with insert and update statement together. The problem is that if query will not be completed(for some reason e.x bad internet connection) my SQL Server table keeps rubbish.

Example of query: