Hi there, It may not be relevant to this mailing list, but I post it here in case somebody knows the answer to help me as a newbie of database designing for the following simple question. Thanks in advance.
I have about 10,000 data samples parsed from web pages. These data are of two types, types A and B, almost 5,000 for each type, to be populated in a single MySQL database (I hope this is a correct approach), but have a question about the table in the database which I should create: All 10,000 data samples have a unique access number, so it should be used as the primary key in the table. Let me say in the table there going to be the following columns: (in Table A) Access_ID primary key column_1 column_2 .... column_last However, these are true only for one of the 2 type, type A, half amount of data (almost 5,000 data samples). For the remaining type, type B data, the table should look like this: (in Table B) Access_ID [identical to those Table A] column_1 column_2 .... column_last [identical to those Table A] EXTREcol_1 (** one extra column) EXTREcol_2 (** another extra column) In a single database, if I am to use Table B, there going to be about 5,000 data samples that would be filled with "null" on these two extra columns, obviously violating the principle of database design. So my question is: how should I create the table in the single MySQL database? Thanks a lot in advance, Robert ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ witty-interest mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/witty-interest
