On 21/07/2003 13:04 Terence Ng wrote:
Hi!
I would like to create a database for products catalogue. I have many products with different specification.
e.g. lamp A: Part no, Color, Raw Material, Wave length, Vf(V)20mA, lv(ucd)10mA
ECG:Part no, Type, Iv, KHz, A, W, Im
Should I put these products in one table, or in separate?
You might be able to do it as one table. Whether that would be the best design, I cannot say. Personally I would approach the problem from 2 different angles.
Firstly I would would list all the possible attributes a part could possibly have. For parts which don't possess a particular attribute, store a null in that column. Draw up a grid or spreadsheet of columns/parts and put an X in every column which would be null for a particular part. If you get lots of X's then a single table might not be the best solution.
Secondly, look at the application from the user's perspective (the use cases). What attributes are to be displayed for different parts? Are they all similar? Do the screens make separate tables seem more natural?
HTH
--
Paul Thomas
+------------------------------+---------------------------------------------+
| Thomas Micro Systems Limited | Software Solutions for the Smaller Business |
| Computer Consultants | http://www.thomas-micro-systems-ltd.co.uk |
+------------------------------+---------------------------------------------+
---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
joining column's datatypes do not match
