I have to create a database with three tables
one for country then State and cities
My Country table is ok.
But i want to include all states of america to my state table and all major cities of each state in america to my city table.
i want any such database so that i can import my database
i need only major cities.
is there a site i can download or copy any such things , exactly as per my requirement
Please help me i'm not finding it in the exact way..
Thanks
This one is Free but you may end up writing a converter code or something to transfer the whole list into Database.
http://www.census.gov/tiger/tms/gazetteer/places2k.txt
I'm sure you could find something with a web search; e.g. "database major cities USA". For example, I found this in the first page of search results ... if you can afford to invest $20.
Wikipedia has a list of US Cities with a population greater than 100,000 people. Does that meet your definition of "major"? If so, check it out.
Related
I'm working on a classified ads site with 12 categories. E.g. category vehicles has items cars, bikes, Commercial Vehicles and spare parts. The following is a flow diagram for posting an ad:
I need to show the specification in the Form Filled section of the above image to the users in dropdown lists in the form when they are posting an advertisement. The car specification will be its color,engine,fuel type.
The ERD is below :
How should this issue be tackled, what are the best practices and is the current design going along the right lines?
On the whole this looks ok. Here are some observations:
likes.iker_id should point at users.id? Just trying to understand your model to start.
I would probably change the pics table to be one pic per row and then add an ordinal for ordering.
One question here is how you intend to look at your graph model. As it is, you might have a graph that could be traversed easily to a depth, a couple deep. I assume you are doing this to recommend ads. If so, I think this is sufficient. If not it would be good to further discuss which rdbms you are targetting.
Hope this helps:
In a simplified case, you will need some extra tables.
So, you are trying to be able to have different specifications for different items in your categories? Or, in other words, it is like having different attributes for different types of products in an e-commerce website.
If that the problem you are tackling, then you should look into the Entity–Attribute–Value (EAV) model that is how the problem is solved. By the way, one of the most popular open source e-commerce engines uses it as well.
i agree look at EAV models...
for some other tables, you have many normalization issues - for example:
you should have a separate address table (not part of the ad)
you should have a picture table (and link those to the ads with another table)
you should have a person table - and link that to the ad as 'owner'
the idea of 'favorite' should also be in this person->ad relationship table as a role or type column
I have a database of US zip codes and their corresponding states, cities and counties. It was supplied as a flat file and I'm trying to normalize the data and figure out exactly which entities depend on which others.
One problem I've come across is that some cities seem to exist in more than one county. I was under the impression that in the US, there is a hierarchy of State -> County -> City -> Zip.
However, this data seems to show otherwise for some cities:
Is my data set incorrect or is this actually a feature of US geography?
I am working with this same topic. I have learned that Virgina has cities that are not within a county. The city functions as both a city and county but in not within any county boundary. Also Alaska has no counties. Their equivilant is Boroughs, but the whole state is not divided into boroughs. Any area not within a borough is referred to as the "unorganized borough".
No, there isn't a clean hierarchy like that.
You're also liable to find cities that straddle state borders (cities in two states), and ZIP codes that take in more than one city. Not long ago, there were ZIP codes that straddled state borders, too. (ZIP codes are more about the route followed to deliver mail than about geography.) There might still be some.
As far as I know, no county is split between two states. But if there happened to be one, it wouldn't surprise me.
Depending on your application, you might discover even weirder things. I used to have to deal with addresses in the mountains that were "in" one county geographically, but were "in" a second county for emergency services (fire, police), and "in" yet a third county for non-emergency services (water, sewer, garbage collection). It depended on where the address was in relation to mountain ridges and roads.
first of all sorry for my bad english hehehe I need some help, I want to design a database for a website, like a mini Amazon. This database will manage every kind of products (TV, cars, computers, books, videogames, penciles, tables, pants...), but also, each product must have some properties (that will be indexed) for example, if the product is a book, the properties will be something like genre, year, author. If the product is a TV, the properties will be something like size, color, also year. And if the product is a car, the properties will be something like year, color, model, for example. So, this is my idea:
One table to manage departments (like electronics, books...)
One table to manage categories of the departments, this table will be a child of the previous. If the department is electronics, here will be audio, tv and video, games... (each category belongs to one department, the relationship is one department to many categories)
One table to manage the products (each product belongs to one category, the relationship is one category to many products)
One table to manage properties (like year, color, genre, model...)
One table to engage products with properties, this table will be called ProductProperties
Im not sure if this is the best way, the database will be huge, I will develop the database on MySQL. But, I think this is not the best way, this article talks about "Database Abstraction: Aggregation and Generalization" http://cs-exhibitions.uni-klu.ac.at/index.php?id=433, in other words generic objects (I think), but this way is old (70s). In this article http://www.simple-talk.com/sql/database-administration/ten-common-database-design-mistakes/ in the section "One table to hold all domain values" says that this is a wrong way... Im saying all of this because of the table ProductProperties, I dont know if I make this table or if I make especific tables for each kind of products.
Do you have any suggestion? Or do you have a better idea?
Thanks in advance, take care!!!
1.One table to manage departments (like electronics, books...)
2.One table to manage categories of the departments, this table will be a
child of the previous. If the
department is electronics, here will
be audio, tv and video, games... (each
category belongs to one department,
the relationship is one department to
many categories)
Why? One table, categories, forming a hierarchy. More flexible.
3.One table to manage the products (each product belongs to one category,
the relationship is one category to
many products)
Why? Allow m:n here. A product in many categorries.
Im not sure if this is the best way,
the database will be huge
Ah - no. Sorry. Nontrivial, yes. Hugh? No. Just to get you an idea of hugh - I have a db I am adding 1.2 billion rows PER DAY to a specific table. On average. THIS is big. YOu end up with what - 100.000 items? not even worth mentioning.
Pablo89, the description of what you want is very close to what the AdventureWorks database for SQL Server does. There are many examples of using AdventureWorks on the Web from web applicatons to reporting to BI.
Download and install SQL Server Express 2008 R2. Download and install the sample database for the above product. Inspect the database design for AdventureWorks.
Use AdventureWorks as examples in questions you may post.
I use AdventureWorks because I use SQL Server. I do not say it is better than other database products I say this because I know AdventureWorks.
I do not think that some database can work fast with 500,000,000 items. Complete tree of products categories for amazon.com contains 51,000 nodes (amazoncategories.info). Also the data is updated hourly, so saved product information can be incorrect. I think the optimal way is to store categories tree only get the product data at runtime using Amazon's API.
I am working in a small law firm and my boss has asked me to put a database together to help with outgoing mail. There are 5 different tables that exist in Access. (Applicants, Attorneys, Lien Claimants, Employers and Workers Compensation Boards) All of the tables include addresses only. Each Applicant has an attorney, one or possibly more lien claimants, employer and designated board. I need to create some type of database that will allow me to create a mail merge for all applicants. Keep in mind each applicant has different addresses, employers, etc..(There are roughly 500 applicants) I need to create the database so when I change/update an address on the table in Access it will change ALL of the applicant(s) it pertains to. Tryin to only update a new address in one place instead of 50. If anyone can help please let me know. I am looking for the most efficient and effective way of doing this.
Store the address in one table and then have a join to the other tables so when you update the address it is reflected in all the other places where it is used.
Have a table "addresses" that has an ID in it.
Have the "applicants" table have an ID in it that refers to the ID in the "addresses" table.
Hopefully this is making sense to you. If not add to the comments and I will try to explain in more
detail.
Just to give you some ideas on setting up a database, here is a library of free database models that cover everything from access control to zoo's.
One of the models is for Lawyers, Cases and Bills, while another is for Case Management. All of these examples give you the fields and relationships. Look over these examples and you should be able to see some ideas of how to setup your tables and relationships to solve your problem.
Good luck and hope this helps some.
I am re-creating a part of my company’s database because it does not meet future needs.
Currently we have mainly a flat file and some disjoined tables that were never fully realized.
My way of thinking is we have a table for each category except maybe the zips table, which may serve as a connect it all together table.
Please refer to image below:
Database Diagram http://www.freeimagehosting.net/uploads/248cc7e884.jpg
One thing I am thinking of is removing the zip table and just putting the zip code in the zipstocities table since the zip code is almost unique and then indexing the table on the zip code. The only downside is zip code has to be a varchar to take care of zip codes with leading zeros. Just want to know if there is a flaw in my logic.
I don't know the US ZIPcode and territorial devision system well, but I assume it's somewhat like the German one.
A state has many counties.
A county has many cities.
A city has many zip codes.
Hence I would use the following schema.
ZipCodes CityZipCodes
------------ ---------------- Cities
ZipCode (PK) <─── ZipCode (PK)(FK) -----------
City (PK)(FK) ───> CityId (PK)
Name
County (FK) ───┐
│
│
Counties │
------------- │
States CountyId (PK) <───┘
----------------- Name
StateId (PK) <─── State (FK)
Name
Abbreviation
Fixed for multiple cities per ZIP code.
One thing you should be aware of is that not all cities are in counties. In Virginia you are in either a city or county but never both.
Looking at the diagram you have, the state table is the only one of the 4 outside tables that is really necessary. Lookup tables with just an ID and a single value aren't worth the effort. These relationships are designed to make a single value in the main table (ziptocities) refer to a set of related data in the lookup table (states).
You'll need to ask yourself why you care about counties. In many states in the US, they have little importance beyond tradition and maps.
The other question will be how important will it be that the address be accurate? How many deaths will there be if important letters are not delivered in a timely manner (possibly many if the letter is about prescription drug recalls!)
You probably want to think about using data from the Postal Service, possibly using a product that corrects addresses. That way, when you get a good address, you'll be certain the mail can be delivered there - because the Postal Service will have said so!
There seem to be flaws in both your process and your logic.
I suggest that you stop thinking about tables and relationships for a moment. Instead, think about facts. Make a list of valid addresses that your database needs to support. Many surprises await you.
Don't confuse an address with a mailing label. They're not at all the same thing. Consider modeling carriers, too. In the US, whether an address is valid depends on the carrier. For example, my PO box is a valid address when the carrier is the USPS, but not when the carrier is UPS.
To save time, you might try browsing some international address formats on bitboost.
Will your logic work if two countries happen to have the same zip code? These two would be pointing to different cities in that case. here are some points to consider
Do you want to use zipcode as a kind
of primary key into address? (at
lease the city, state and country
fields). In that case, you can have
zipcode, city,state,country in one
table. Create indexes on city, state
etc.. (you have a functional
dependency of the form
zipcode->country,state,city . This
as i said may not be true across
countries.
If auto populating is
your only concern, create a
materialized view and use it.
I would recommend reading 'Data Model patterns' by David C. Hay.
But not every person who has a valid medical claim is required by law to remain in the US until the claim is settled. People move.
San Francisco is a city in California; it's not a city in Alabama. Does your design prevent nonsense entries like "San Francisco, AL"?