Sunday, April 29, 2012

Tips on Database Design and Use:


Introduction to Database:
Databases can be a great tool to organize information, track statistics and generate reports. Like any tool, however, they must be used correctly. A badly designed or improperly used database will end up creating problems rather than solving them. Here are some tips to facilitate proper database design and use:
 1)Create one flat file:
A flat file means that all your data goes on one data table. Flat files make it difficult to create statistical reports.
2)Create relational data tables:
Unless you are doing only one very simple task, such as entering a list of names and addresses, you will need more than one table of data to track your information correctly.
1)Create repeating fields:
If you have fields like Date1, Date2, Date3, you should look at your data table design. Repeating fields are usually the sign of a flat file design, and will make reporting difficult.
2)Put like data in a single field:
Create separate relational tables and you will eliminate the need for most repeating fields.
1)Create repeating fields:
If you have fields like Date1, Date2, Date3, you should look at your data table design. Repeating fields are usually the sign of a flat file design, and will make reporting difficult.
2)Put only 1 piece of data in a field:
Relational databases are set up so that the user doesn’t need to put more than 1 piece of data in a field.
1)Use a range instead of a number:
When entering data such as income levels, set up the database so that you are entering numbers, not a range such as $10,000 – $15,000. Ranges are not very flexible should the categories change later on.
2)Use a number instead of a range:
If you enter a number in an income field, you will be able to generate reports that can easily be changed if the categories change.
1)Enter data inconsistently:
If some users enter “donor” and others enter “contributor,” database queries will be hard to run accurately.
2)Decide on consistent rules for data entry:
The organization should make decisions about data entry consistency. Then the database designer can build in ways to enforce consistency at the user level.
1)Create too many address-oriented fields:
Some databases include so many fields connected to addresses, that creating labels is impossible.
2)Create only necessary address fields:
Keep address-oriented fields to a number that will fit on mailing labels.
1)Use too many Yes/No fields:
If you are using a large number of yes/no fields, you may need to re-examine the design of your database.
2)Create only necessary address fields:
Keep address-oriented fields to a number that will fit on mailing labels.
1)Enter the wrong type of data in a field:
Sometimes users cannot find the proper field for a piece of data, so they enter it into another field, such as typing a client’s ethnicity in an empty Address2 field. 2)
2)Enter information in the proper field:
If the data entry person cannot find the right place for a piece of data, perhaps the database needs some work. The answer is not to enter information randomly in an empty field.

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