I have a question about web usability related with tables, this is my use case:
I have a view with more than 1 table, I mean, I have N>0 tables in the view and each table has a title (for example "Photo list", "Video list", "Sound list").
Using javascript, users have the possibility to change the "view level", I mean, the detail level of the view. This means that clicking in different action buttons (basic, medium, advance view) the users can modify the amount of rows in each table. So, could be that some of the tables would be empty (no rows).
My question: What is the best usability practice to manage empty tables?
When you have identified tables that shows certain information you shouldn't hide then when they are empty, at least not without showing in any way that there's no data related to the empty table.
If you don't show the table maybe your users don't perceive that there is an entity of data that's empty, if you show it they will. This is important.
It could, however, be less important depending on the way you are showing your data. Let's say, for example, that your view shows on top a list of the different data types with the number of records in each one. If you keep a reminder there that X data type has 0 records, you can hide the table header on the view body, as all the info your user need is on the view.
On the contrary, if your users have no way to know that a specific data type is empty other than seeing an empty table, you need to keep it in your view to avoid them loosing information.
Keep in mind that information is the key on our world. Design is important to help and improve user experience, but you shouldn't put it before information.
Related
I am struggling with an issue in designing my Access database.
I am a caregiver, and part of my job is taking clients out into the community. I am attempting to build a catalog of outings to help the employees at our company come up with and store ideas for these. I want to store information for each of up to 5 types of events that clients can do at a location. That information includes the event type, when it runs and doesn't, and how much it'll cost, all of which would be user-selectable. (Separately in the same table, I want to include contact information and information that helps the user search for event locations, such as the ZIP code.) I have attempted to normalize the database by spreading event information across fields in the main table, linked to lookup tables. I am aware that Access has a limit of 32 relationships per table.
To help staff find event types, I am trying to set up a method for categorizing them. That requires setting up nested lookup tables, as shown in the first picture.
If I understand correctly, the additional "copies" of those lookup tables are aliases. When I save the setup for the relationships between those aliased lookup tables, close the Relationships window, and open it again, I find Access has changed them, as shown in the second picture. This happens whether I delete the lookup table information for each field in Datasheet View. I don't understand why it does this or how to fix it.
To answer your question:
In the object browser I see that you have only one table: t_OutingType. Therefore, the "tables" t_OutingType_2, t_OutingType_3 are just aliases; "pointers" to the same table (like a shortcut to a document). When you save the relationships and close the window, the relationship information is written to the metadata of the database. When you re-open the Relationships window Access re-builds the relationship diagram from the metadata, and it does not include the redundant aliases.
Additional advice:
Whenever you find yourself duplicating columns in a table, e.g., Event_1, Event_2, ... a little voice in your head should start shouting "Are you sure that's a good idea?" Imagine if you want to search the database for events that fall on a certain date. With the table layout described above you would need to ...
SELECT ... WHERE EventDate_1 = [theDate] OR EventDate_2 = [theDate] OR EventDate_3 = [theDate] ...
It's almost always better to split the Event information into a separate child table and maintain an association table between the child table and its parent.
I have a web page which feeds users data in HTML tabular format. The table can be quite complex and long (say 40-50 columns in total). Different users will be interested in different columns, so to accommodate, the user has the ability to modify the columns of the table to his own preferences, so that he can:
change their width
change their order
set them hidden
(Each table has a unique table-id, and each column in a table has a unique Id within that table.)
The problem, of course, is that the next time the user uses the website, he won't want to spend time again re-configuring his preferences. So my website needs to store his preferences (which I can do in his database profile).
But what is the best way of storing the required data, so that (using JavaScript) I can re-draw the table for the user, as he last left it?
I can use either XML or JSON as a technical platform for storing the required information.
But the question is, what is the best format for storing each column's width, position and visibility, in such a way that my JavaScript can redraw his screen with minimum processing?
The problem, really, is that sometimes I need to access the column's data by referencing the column ID, and other times by its numeric position. So sometimes an object would be a better option, and sometimes an array.
Interested to know how other people store this kind of data.
--EDIT--
To re-word the question (and abstract away from the real world situation of HTML tables), I suppose what I really want to know is:
How do I best store data in such a way that I can access it by both
its ID (primary-key) and Numeric-Index, given that the Index of the ID
(primary-key) can change over time.
Which one would be better (performance wise and maintenance), a database which creates table dynamically or just adding rows dynamically?
Suppose I am building a project in which I let users to register. Say I have a table which store only basic personal infos, like name, dob, Date of joining, address, phone, etc. Say 10 columns.
Now is the tricky part.
Scene 1: Creating multiple tables
When a user complete registration, a message table is created. So each table is created for each users. The rows of each message table varies for each user.
In the same way there is a cart table for each user like the message table.
For this scene 1, 2 tables are created with every registration.
Scene 2: Adding Rows
The scenario is same here as well, but in this case I have 2 tables for message and cart. Rows are added only when there is an activity.
Note:
You must assume that the number of users is more than 2000 and expect 50+ users to be active all the time. Which means the message and cart tables are always busy for both the cases. Like there is always a query for update, add, delete, insert, select etc. simultaneously.
Also which scene will consume more disk space.
While writing this, it make me wonder what technique would Facebook and others use. If they use the Scene 2 style (all users (billions) use the same big long message table)... Just wondering
Databases has some basic rules defined for Database Design called
"Database Normalization", These basic rules allow us eliminating
redundant data.
1st Normal Form
Store One piece of information in only One Column, A column should store only One piece of information.
2ns Normal Form
A Table should have only the columns that are related to each other. All the related columns should be in One table.
Now if you look at your advised design, A Separate Table for each USER
will split SAME information/Columns about all the user in 1000's of
tables. Which violates the 2nd Normal Form.
You need to Create One Table and put all the related Columns in that
one table for all the users. and you can make use of normal t-sql to
query your data but if you have a table for each user my guess is your
every query that you execute from your application will be built
dynamically and for every query you will be using dynamic sql. which
is one of the Sql Devils and you want to avoid using it whenever
possible.
My suggestion would be read more about Database Design. Once you have
some basic understanding of database design. Draw it on a piece of
paper and see if it provides you everything that your business
requires / expects from this application , Spend sometime on it now it
will save you a lot of pain later.
In an mysql table I would like to get data from user, however the data would need to be moderated by admin first. My question is that is it normal to just insert into the original table and use a field as flag of the moderation status? Or have a separate table of pre-moderated posts and do the insertions only at moderation?
I think both method would work but I am not sure if I miss out other considerations here. Hope someone experienced can tell me the established/preferred way to do that.
If you're working with a not-huge data set I'd recommend just adding a flag column that allows you to show or hide user data. This will require fewer and easier queries to work with and should make your life a lot easier than juggling the data between multiple identical tables. Additionally, if you want to add something like a button for "report this content as BAD" you could remove the content from other results while only "soft deleting" it from public visibility.
I'm writing a CMS for various forms and such, and I find I'm creating a lot of drop-downs. I don't really feel like mucking up my database with tons of random key/string value tables for simple drop-downs with 2-4 options that change very infrequently. What do you do to manage this in a responsible way?
This is language-agnostic, but I'm working in Rails, if anyone has specific advice.
We put everything into a single LookUp table in the database, with a column that mapped to an enum that described which lookup it was for (title, country, etc.).
This enabled us to add the flexibility of an "Other, please specify" option in lookup dropdowns. We made a control that encapsulated this, with a property to turn this behaviour on or off on a case-by-case basis.
If the end user picked "Other, please specify", a textbox would appear for them to enter their own value. This would be added to the lookup table, but flagged as an ad hoc item.
The table contained a flag denoting the status of each lookup value: Active, Inactive, AdHoc. Only Active ones would appear in the dropdown; AdHoc ones were those created via the "Other, please specify" option.
An admin page showed the frequency of usage of the AdHoc values, allowing the administrators of the site to promote common popular values into general usage (i.e. changing their Status flag to Active).
This may well be overkill for your app, but it worked really well for ours: the app was basically almost entirely CRUD operations on very business-specific data. We had dozens of lookups throughout the site that the customer wanted to be able to maintain themselves. This gave them total flexibility with no intervention from us.
You cold have one single dropdown table with an extra column to say what the drop down is for... limit the results with a where clause...
At my current position, we implemented a LookupCode table that contains a CodeGroup,Code, and Meaning column, as well as some others (like active). That way you have a single table that contains all of your lookup values are in a single location and you can do some quick lookups to bind to your dropdown lists.