I'm using selenium to automate interaction with a table on a webpage.
The table has a few columns and I'm sorting the data in the table by clicking on the sortable-headers (column names)
I've used a switch-case statement such as
switch(columnName){
case: "firstname":
columnHeader=driver.findElement(By.xpath());
case: "lastname":
columnHeader=driver.findElement(By.xpath());
...
...
and so on.
}
What could be a better alternative to using switch-case.
Also I used this since I didn't want to write a separate method for each column.
My suggestion is to go ahead and write a method to sort the table for each column. This prevents a few problems... 1) consumers don't have to look at the page to remember what all columns are available to sort by, 2) consumers don't have to look at the code for the function you are writing to understand what string they need to pass to sort by the desired column, 3) you don't have to worry about handing bad strings, 4) consumers don't have to worry about passing a bad string, and so on. Many of these problems won't be caught at compile time which means you will (or may) find them when the script is running. You want to give preference to finding as many bugs as possible at compile time. It will save you a LOT of time and prevent a LOT of bugs down the road.
Other benefits are that consumers look at the API and see methods like .sortTableByFirstName(), .sortTableByLastName(), etc. and it's obvious what each function does and it moves bugs into compile time because you can't call some method that doesn't exist because the name was typo'd.
Related
I have a table named buildings
each building has zero - n images
I have two solutions
the first one (the classic solution) using two tables:
buildings(id, name, address)
building_images(id, building_id, image_url)
and the second solution using olny one table
buildings(id, name, address, image_urls_csv)
Given I won't need to search by image URL obviously,
I think the second solution (using image_urls_csv column) is easier to use, and no need to create another table just to keep the images, also I will avoid the hassle of multiple queries or joining.
the question is, if I don't really want to filter, search or group by the filed value, can I just make it CSV?
On the one hand, by simply having a column of image_urls_list avoids joins or multiple queries, yes. A single round-trip to the db is always a plus.
On the other hand, you then have a string of urls that you need to parse. What happens when a URL has a comma in it? Oh, I know, you quote it. But now you need a parser that is beyond a simple naive split on commas. And then, three months from now, someone will ask you which buildings share a given image, and you'll go through contortions to handle quotes, not-quotes, and entries that are at the beginning or end of the string (and thus don't have commas on either side). You'll start writing some SQL to handle all this and then say to heck with it all and push it up to your higher-level language to parse each entry and tell if a given image is in there, and find that this is slow, although you'll realise that you can at least look for %<url>% to limit it, ... and now you've spent more time trying to hack around your performance improvement of putting everything into a single entry than you saved by avoiding joins.
A year later, someone will give you a building with so many URLs that it overflows the text limit you put in for that field, breaking the whole thing. Or add some extra fields to each for extra metadata ("last updated", "expires", ...).
So, yes, you absolutely can put in a list of URLs here. And if this is postgres or any other db that has arrays as a first-class field type, that may be okay. But do yourself a favour, and keep them separate. It's a moderate amount of up-front pain, and the long-term gain is probably going to make you very happy you did.
Not
"Given I won't need to search by image URL obviously" is an assumption that you cannot make about a database. Even if you never do end up searching by url, you might add other attributes of building images, such as titles, alt tags, width, height, etc, so you would end up having to serialize all this data in that one column, and then you would not be able to index any of it. Plus, if you serialize it with one language, then you or whoever comes after you using a different language will either have to install some 3rd party library to deserialize your stuff or write their own deserialization function.
The only case that I can think of where you should keep serialized data in a database is when you inherit old software that you don't have time to fix yet.
I am changing the command text for a data set inside the .rdl ffile:
I would like to know how can I update the resulting fields that are returned by the select statement:
I know that these fields must be automatically generated, so I was wondering if it's possible to update them right after editing the SQL code inline??
Usually when someone wants to have a look at the data in command text they are wanting it for reference to an end user(from what I have seen). You may want to amend it but ultimately with reporting your first goal should be: "What am I doing this for?" If your goal is dynamic creation at runtime then I would avoid this and offer a few other suggestions:
Procertize it. Making a stored procedure if you have the know how in SQL Server is a convenient and fast way to get what you want and you can optimize it if you know what you are doing with your SQL FU to get good results. The downside would be if you work with multiple environments you have to deploy your code for the TSQL as well as the RDL file.
Use an expression to build the dataset at runtime. In cases where I have been told that the query itself was not properly optimized by other developers they have mentioned doing this. I myself do not always see the advantage of doing this versus just having your predicate construction work well with good indexing on the source engine. Regardless you can build your dataset at runtime. It would be similar to hitting 'fx' next to the text and then putting in something like this(assuming you have a variable named #Start):
="Select thing
from table
Where >= " & Parameters!Start.Value
Again I have not really seen if this is really that much faster than:
Select thing
from table
Where >= #Start
But it is there if you just want to build it dynamically.
You can try to build your expression dynamically from parameters being PART of the select statement. SSRS is all about the 'expressions' and what you can do with them. Once you jump in and learn how they apply to everything you can go nuts so to speak on using them. A general rule though is the more of them you use and rely on the slower your reports will become.
I hope some of this may help, I would ask first is something dynamic due to a need to be event driven or is performance related.
What drawbacks can you think of if I design my REST API with query strings without parameter values? Like so:
http://host/path/to/page?edit
http://host/path/to/page?delete
http://host/path/to/page/+commentId?reply
Instead of e.g.:
http://host/api/edit?page=path/to/page
http://host/api/delete?page=path/to/page
http://host/api/reply?page=path/to/page&comment=commentId
( Edit: Any page-X?edit and page-X?delete links would trigger GET requests but wouldn't actually edit or delete the page. Instead, they show a page with a <form>, in which page-X can be edited, or a <form> with a Really delete page-X? confiramtion dialog. The actual edit/delete requests would be POST or DELETE requests. In the same manner as host/api/edit?page=path/to/page shows a page with an edit <form>. /Edit. )
Pleace note that ?action is not how query strings are usually formatted. Instead, they are usually formated like so: ?key=value;key2=v2;key3=v3
Moreover, sometimes I'd use URLs like this one:
http://host/path/to/page?delete;user=spammer
That is, I'd include a query string parameter with no value (delete) and one parameter with a value (user=spammer) (in order to delete all comments posted by the spammer)
My Web framework copes fine with query strings like ?reply. So I suppose that what I'm mostly wondering about, is can you think of any client side issues? Or any problems, should I decide to use another Web framework? (Do you know if the frameworks you use provides information on query strings without parameter values?)
(My understanding from reading http://labs.apache.org/webarch/uri/rfc/rfc3986.html is that the query string format I use is just fine, but what does that matter to all clients and server frameworks everywhere.)
(I currently use the Lift-Web framework. I've tested Play Framework too and it was possible to get hold of the value-less query strings parameters, so both Play and Lift-Web seems okay from my point of view.)
Here is a related question about query strings with no values. However, it deals with ASP.NET functions returning null in some cases: Access Query string parameters with no values in ASP.NET
Kind regards, Kaj-Magnus
Query parameters without value are no problem, but putting actions into the URI, in particular destructive ones, is.
Are you seriously thinking about "restful" design, and having a GET be a destructive action?
In a custom ContentProvider I need to filter out some columns specified in the inputs. Given the text-oriented Android interfaces this is giving me a hard time.
For example the input on MyContentProvider.query() would effectively ask something like:
SELECT column_a, column_b FROM my_table WHERE column_a=1 AND column_b=red;
The problem is that at this particular MyContentProvider _column_b_ might not make any sense and would not be present in the table. Filtering the projection so that only relevant columns remain can be easily done since it's a String[]. However, filtering the String "where" (selection) and "selectionArgs" inputs for these columns is not trivial. If done properly it would become:
SELECT column_a FROM my_table WHERE column_a=1;
Otherwise one would get a SQLiteException "no such column".
So, is there any easy way to ignore or filter columns from such an sql statement or do I need to go and write some smart albeit very limited regexp parsing code for the selection part?
The reason I'm not getting the right inputs is because I maintain a custom ContentProvider as an interface to address, but I talk to multiple custom ContentProviders herein (in the background). One way or another, I would need to filter the selection somewhere.
Please note that I am not asking simply how to do a query or use the SELECT ... WHERE statement. However it concerns my implementation of the query() function.
Since you are extending your MyContentProvider with ContentProvider why don't you just overload the query() method?
Look at ContentProvider - Sharing Content using the ContentProvider for someone elses example on how to create a custom ContentProvider. You should have full control over what data you fetch from your SQLiteDatabase.
More importantly, look at the arguments provided to query(), as they contain the information you need to you in a way where you can dynamically build the query from what is passed into the method call.
Depending on if you can find a good query builder, you have an opportunity to build a small but powerful abstraction layer to build your queries, so that you minimize the amount of actual SQL that you write yourself.
Also, always remember to sanitize your inputs!
I've run into an issue with an autocomplete field I'm working on. The field I'm working with is composed of the form "<NAME> (<CODE>)". When a user starts typing in text, I want to display any results that match either NAME or CODE.
For example, if this list contains items and their codes, like "Personal Computer (PC)", then I'd want the list to pop up that row if the user types "P", "PC", "Per", etc.
I've gotten this to work fine in SQLite with a query like this:
SELECT *
FROM table
WHERE name LIKE "?%" or code LIKE "?%"
However, the problem I'm running into now is how to best sort the results that come back from this. For example, If someone enters "PC", I want "Personal Computer (PC)" to be the first result. However, if there's another row (you'll have to bear with me as this is contrived) "PC Case (301)", then there's no simple ordering I can do on the results to ensure that the best match appears first. Ordering by name and code both returns PC Case first.
I want a query where it returns the best match first, rather than items in alphabetical order. Is there such a function I can use in SQLite to get this, or should I return the results and then mess with the order in the code?
If it helps any, I'm using this for FilterQueryProviders on Android.
Yes, you should implement FullTextSearch and the use MATCH in your queries.
Ref: http://dotnetperls.com/sqlite-fts3
This is a long time after the fact, but I've solved my dilemma without having to resort to crazy sorting tactics.
Basically, once an autocomplete gets complex enough, you need to implement your own CursorAdapter (implementing FilterQueryProvider) then override convertToString(). That way, you end up being able to do complex queries via runQuery(), but can then convert it to readable form in convertToString().