I am developing a health care system and I want the doctor when starting to type a diagnosis instead of typing it , he can select from a list that will be displayed for him.
the list contains diseases or symptoms that will then be inserted into database in a diagnosis table.
I did that because of two reasons:
I want all doctors to use the same list of symptoms when writing their diagnosis to work on that data later on, instead of each one typing his own way.
The data will be localized and translated to different languages when displayed to different regions.
I am facing a problem here, should i put all these in a lookup table in a database or a config file ? given that number of rows are 3000 in 7 languages ( each language will have it's own column ) and i may at anytime add new data or remove.
I would put them in a database. I find it easier to maintain, and faster to query than a config file.
Related
I'm working with an existing MS SQL database and ASP.NET web application. An update is needed in a table, but in order to add the new data and have it display correctly in the site, I need to be able to take a series of existing records, essentially "push them down", and then add the new data in the open space created.
Is there a cleaner, more efficient method than by just creating a new record that's a copy of the last related record, and then essentially doing a copy-and-paste for the remaining records until I reach the insertion point? There are quite a few records to move and I'd prefer something that isn't as mind-numbing and potentially error-prone as that.
I know the existing site and database isn't designed optimally for inserting new data into this table unless it's added to the end, but reconfiguring the database and stored procedures is not an option I presently have.
-- EDIT --
For additional requested information...
Screen shot of table definition:
Screen shot of some table data (filtered by TemplateID):
When looking at the table data, there are a couple other template ID values that bring back a bit more complex data. The issue is that this data needs to maintain this order, which happens to be the order in which it has been entered, since it gets returned and displayed in the shown order. The new data needs to be entered prior to one of these lettered subject headers. Honestly, I think this is not the best way to do this, but I had no hand in the design. It was created by a different company, and mine was hired to handle updates and maintenance after the creators became unpleasant to work with. A different template ID value brings back two levels of headers, which doesn't make my task any easier or alterations much cleaner considering the CS code that calls the stored procedures is completely separated from the code that builds the contents of the pages, and the organizational structure i tough to follow. There are some very poor naming conventions in places.
At any rate, there needs to be an insertion into this group of data under the "A" header value. The same needs to occur with another chunk associated with a different template ID, and there is another main header below the insertion point:
I'm making an api for movie/tv/actors etc. with web api 2 and sql server. The database now has >30 tables, most of them storing data users will be able to edit.
How should I store old version of entries?
Say someone edits description, runtime and tagline for a entry(movie) in the movies table.
I'll have a table(movies_old), where I store the editable files in 'movies' pluss who/when it was edited.
All in the same database. The '???_old' tables has no relationships.
I'm very new to database design. Is there something obviously wrong with this?
To my mind, there are two issues here: what table you store the data in, and what goes in the "historical value" field.
On the first question, there are two obvious options: Store old and new records in the same table, with some sort of indication of which is "current" and which is "history", or have a separate table for history.
The main advantage of one table is that you have a simpler schema. This is especially true if the table contains many fields. If there are two tables, then all the field definitions are duplicated. When you move data from the current table to the history table, you have to copy every field, and if the list of fields changes, or their formats change, you have to remember to update the copy. Any queries that show the history have to read two tables. Etc. But with one table, all that goes away. Converting a record from current to history just means changing the setting of the "is_current" flag or however you indicate it.
The main advantages of two tables are, (a) Access is probably somewhat faster, as you don't have so many irrelevant records to skip over. (b) When reading the current table you don't have to worry about excluding the history records.
Oh, an annoying thing about SQL: In principle you could put a date on each record, and then the record with the latest date is the current one. In practice this is a pain: you usually have to have an inner query to find the latest date, and then feed this back in to an outer query that re-reads the record with that date. (Some SQL engines have ways around this. Postgres, for example.) So in practice, you need an "is_current" flag, probably 1 for current and 0 for history or some such.
The other issue is what to put in the contents. If you're dealing with short fields, customer number and amount billed and so forth, then the simple and easy thing to do is just store the complete old contents in one record and the complete new contents in the new record. But if you're dealing with a long text block, like a plot synopsis or a review, there could be many small editorial changes. If every time someone fixes a grammar or spelling error, we have a whole new record with the entire 1000 characters, of which 5 characters are different, this could really clutter up the database. If that's the case you might want to investigate ways to store changes more efficiently. May or may not be an issue to you.
I am stuck on a database problem for a client, wandering if someone could help me out. I am currently trying to implement filtering functionality so that a user can filter results after they have searched for something. We are using SQL Server 2008. I am working on an electronics e-commerce site and the database is quite large (500,000 plus records). The scenario is this - user goes to our website and types in 'laptop' and clicks search. This brings up the first page of several thousand results. What I want to do is then
filter these results further and present the user with options such as:
Filter By Manufacturer
Dell (10,000)
Acer (2,000)
Lenovo (6,000)
Filter By Colour
Black (7000)
Silver (2000)
The main columns of the database are like this - the primary key is an integer ID
ID Title Manufacturer Colour
The key part of the question is how to get the counts in various categories in an efficient manner. The only way I currently know how to do it is with separate queries. However, should we wish to filter by further categories then this will become very slow - especially as the database grows. My current SQL is this:
select count(*) as ManufacturerCount, Manufacturer from [ProductDB.Product] GROUP BY Manufacturer;
select count(*) as ColourCount, Colour from [ProductDB.Product] GROUP BY Colour;
My question is if I can get the results as a single table using some-kind of join or union and if this would be faster than my current method of issuing multiple queries with the Count(*) function. Thanks for your help, if you require any further information please ask. PS I am wandering how on sites like ebay and amazon manage to do this so fast. In order to understand my problem better if you go onto ebay and type in laptop you will
see a number of filters on the left - this is basically what I am trying to achieve. I don't know how it can be done efficiently when there are many filters. E.g to get functionality equivalent to Ebay I would need about 10 queries and I'm sure that will be slow. I was thinking of creating an intermediate table with all the counts however the intermediate table would have to be continuously updated in order to reflect changes to the database and that would be a problem if there are multiple updates per minute. Thanks.
The "intermediate table" is exactly the way to go. I can guarantee you that no e-commerce site with substantial traffic and large number of products would do what you are suggesting on the fly at every inquiry.
If you are worried about keeping track of changes to products, just do all changes to the product catalog thru stored procs (my preferred method) or else use triggers.
One complication is how you will group things in the intermediate table. If you are only grouping on pre-defined categories and sub-categories that are built into the product hierarchy, then it's fairly easy. It sounds like you are allowing free-text search... if so, how will you manage multiple keywords that result in an unexpected intersection of different categories? One way is to save the keywords searched along with the counts and a time stamp. Then, the next time someone searches on the same keywords, check the intermediate table and if the time stamp is older than some predetermined threshold (say, 5 minutes), return your results to a temp table, query the category counts from the temp table, overwrite the previous counts with the new time stamp, and return the whole enchilada to the web app. Otherwise, skip the temp table and just return the pre-aggregated counts and data records. In this case, you might get some quirky front-end count behavior, like it might say "10 results" in a particular category but then when the user drills down, they actually find 9 or 11. It's happened to me on different sites as a customer and it's really not a big deal.
BTW, I used to work for a well-known e-commerce company and we did things like this.
This is more of a question for experienced people who've worked a lot with multilingual websites and e-shops. This is NOT a database structure question or anything like that. This is a question on how to store a multilingual website: NOT how to store translations. A multilingual website can not only be translated into multiple languages, but also can have language-specific content. For instance an english version of the website can have a completely different structure than the same website in russian or any other language. I've thought up of 2 storage schemas for such cases:
// NUMBER ONE
table contents // to store some HYPOTHETICAL content
id // content id
table contents_loc // to translate the content
content, // ID of content to translate
lang, // language to translate to
value, // translated content
online // availability flag, VERY IMPORTANT
ADVANTAGES:
- Content can be stored in multiple languages. This schema is pretty common, except maybe for the "online" flag in the "_loc" tables. About that below.
- Every content can not only be translated into multiple languages, but also you could mark online=false for a single language and disable the content from appearing in that language. Alternatively, that record could be removed from "_loc" table to achieve the same functionality as online=false, but this time it would be permanent and couldn't be easily undone. For instance we could create some sort of a menu, but we don't want one or more items to appear in english - so we use online=false on those "translations".
DISADVANTAGES:
- Quickly gets pretty ugly with more complex table relations.
- More difficult queries.
// NUMBER 2
table contents // to store some HYPOTHETICAL content
id, // content id
online // content availability (not the same as in first example)
lang, // language of the content
value, // translated content
ADVANTAGES:
1. Less painful to implement
2. Shorter queries
DISADVANTAGES:
2. Every multilingual record would now have 3 different IDs. It would be bad for eg. products in an e-shop, since the first version would allow us to store different languages under the same ID and this one would require 3 separate records to represent the same product.
First storage option would seem like a great solution, since you could easily use it instead of the second one as well, but you couldn't easily do it the other way around.
The only problem is ... the first structure seems a bit like an overkill (except in cases like product storage)
So my question to you is:
Is it logical to implement the first storage option? In your experience, would anyone ever need such a solution?
The question we ask ourselves is always:
Is the content the same for multiple languages and do they need a relation?
Translatable models
If the answer is yes you need a translatable model. So a model with multiple versions of the same record. So you need a language flag for each record.
PROS: It gives you a structure in which you can see for example which content has not yet been translated.
Separate records per language
But many times we see a different solution as the better one: Just seperate both languages totally. We mostly see this in CMS solutions. The story is not only translated but also different. For example in country 1 they have a different menu structure, other news items, other products and other pages.
PROS: Total flexibility and no unexpected records from other languages.
Example
We see it like writing a magazine: You can write one, then translate to another language. Yes that's possible but in real world we see more and more that the content is structurally different. People don't like to be surprised so you need lots of steps to make sure content is not visible in wrong languages, pages don't get created in duplicate etc.
Sharing logic
So what we do is most time: Share the views, make the buttons, inputs etc. translatable but keep the content seperated. So that every admin can just work in his area. If we need to confirm that some records are available in all languages we can always trick that by creating a link (nicely relational) between them but it is not the standard we use most of the time.
Really translatable records like products
Because we are flexible in creating models etc. we can just use decide how to work with them based on the requirements. I would not try to look for a general solution which works for all because there is none. You need a solution based on your data.
Assuming that you need a translatable model, as it is described by Luc, I would suggest coming up with some sort of special-character-delimited key-value pair format for the value column of the content table. Example:
#en=English Term#de=German Term
You may use UDFs (User Defined Functions in T-SQL) to set/get the appropriate term based on the specified language.
For selecting :
select id, dbo.GetContentInLang(value, #lang)
from content
For updating:
update content
set value = dbo.SetContentInLang(value, #lang, new_content)
where id = #id
The UDFs:
a. do have a performance hit but this also the case for join that you will have to do between the content and content_loc tables
and
b. are somehow difficult to implement but are reusable practically throughout your database.
You can also do the above on the application/UI layer.
I'm going to try to keep this question database agnostic, but I have an interesting problem that I need to tackle and I thought I'd open up the floor for suggestions and feedback.
I need to be able to download data from a feed source and store it in a database of some kind, the data needs to be merged into the existing data and I need to able to query for the data as of any given date. It's the part in bold that I'd like to talk about.
Essentially what this problem boils down to is that I need to persist an object graph to an OLTP database and be able to query it temporally.
In the simple case of one table this problem is very simple, you have a date range indicating the valid time span for the record and then you pass in an as of range and only select rows that are valid for this point in time. The issues rise when you have more than one table.
Let's take the case of having two tables, Order-*Item.
When we query for an order we can apply the same as of date changes to the item table. All is well, but what happens if we want to modify an order? Now we need to copy the order row, set the date ranges so the valid from on the new row and the valid to on the new row is set to now. We also have to copy the items, or if we change our model copy the references to the items.
Even in this simple case things are starting to get complicated.
My problem is exacerbated because I have a self-referential object graph, so to use the above model you'd have Order-*Item-*Order.
What would you do? How do you structure your databases when you need versioning of rows and temporal queries?
Back in the day, Developing Time-Oriented Database Applications in SQL was the best source of info for temporal databases. Published in 1999, the copyright has reverted to the author, and the link goes to his PDF version of the book. Look here for more of his publications, and for a link to the compressed content of the CDROM.