Re: multi table relational databases
What does having 14 Tables/DBs have to do with the Palm only having 16 categories? (really only 15 if you count the obligatory 'all' category). Category use is definable or ignoble by the programmer. To get around the # limitation, you just ignore the PDB built in category mechanism and use your own if need be. I've seen applications from other developers with essentially an unlimited # of categories. - Original Message - From: Bob Whiteman [EMAIL PROTECTED] To: Palm Developer Forum palm-dev-forum@news.palmos.com Sent: Thursday, July 27, 2000 1:58 PM Subject: RE: multi table relational databases Well 14 tables raises a new concern. You can only have 16 categories in a Palm database. If you were to add a couple more tables to your already extensive database you'll be out of luck. -- For information on using the ACCESS Developer Forums, or to unsubscribe, please see http://www.access-company.com/developers/forums/
RE: multi table relational databases
Well 14 tables raises a new concern. You can only have 16 categories in a Palm database. If you were to add a couple more tables to your already extensive database you'll be out of luck. Having multiple handles open at the same time is not an issue in itself. It's not like an Oracle or Sybase database where you have to be concerned about a limited resource such as database connections. The only issue with that is managing 14 DmOpenRefs instead of just one. One other reason to use separate Palm databases for each table is that it's more maintainable. For instance: Palm databases have a version attribute. If you update your application and update one of your tables you can simply increment that version attribute of the Palm database in new releases. You can easily detect when a user has an old version of that table and upgrade or delete it. If all your tables are in one Palm database, however, you only have one version for all your database tables. -Bob Whiteman -Original Message- From: K. Chugh [mailto:[EMAIL PROTECTED] Sent: Thursday, July 27, 2000 11:26 AM To: Palm Developer Forum Subject: Re: multi table relational databases hi bob. thanks for the reply. i am looking at like 14 or so tables, and i figured i don't want all those handles open at the same time. this is my first database program so i'm not sure if this is a rational concern or not. some of the tables will have only a few records, while others will have as many as a few thousand records. do you think i should actually implement one database for each table instead of one database with a table id? thanks, kevin -- For information on using the ACCESS Developer Forums, or to unsubscribe, please see http://www.access-company.com/developers/forums/
RE: multi table relational databases
I've implemented a fairly simple relational database for an appliation. One problem with your suggested approach below is that it may be very tricky to sort the tables. Also, searches and inserts will take longer because they have to deal with a much larger Palm database. I used separate Palm databases for each table in the logical database. That way each table can have its own simple sort routine. Is there any particular reason why you don't want to create multiple Palm databases? -Bob Whiteman -Original Message- From: K. Chugh [mailto:[EMAIL PROTECTED] Sent: Thursday, July 27, 2000 7:45 AM To: Palm Developer Forum Subject: multi table relational databases hi- i'm paranoid about introducing a new layer to my apps by using sybase ultralite, etc. does anyone know of any techniques for using multi table databases? i was thinking of opening one database and using the category for the table identifier then just inserting records in the appropriate table. has anyone tried this? thanks, kevin -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/ -- For information on using the ACCESS Developer Forums, or to unsubscribe, please see http://www.access-company.com/developers/forums/
Re: multi table relational databases
I programmed an app that uses 3 databases, and they're set up in a one to many relationship. It works great. I even have a delete which will work through the sub databases and delete useless records in them too. (Basically what a database is to plam, is what I consider a table... so if it's easier to think of it that way, do so.) I didn't have to use categories to do this. I just created a field in my 2 sub databases called ID which I stored the Unique ID of the previous record in each sub record created. This allows only certain records to be displayed if you want, and certain records to be deleted. Works like a charm ;-) + Timothy D. Astle Embedded Systems Programmer ALT Group Inc. + People on Jolt cola write the funniest things. A-10 Obedience Guide, Kitty Hawk Studios -- For information on using the ACCESS Developer Forums, or to unsubscribe, please see http://www.access-company.com/developers/forums/
Re: multi table relational databases
i was thinking of opening one database and using the category for the table identifier then just inserting records in the appropriate "table." has anyone tried this? I'm not sure I totally understand your proprosal, but I've done something like what I think you're describing. I created a record type field (because I was using the category for something else) to simulate multiple tables in one file. The code got kind of messy (probably my coding, not the technique), but it worked fine. Regards, Steve Mann -- --- Creative Digital Publishing Inc. 1315 Palm Street, San Luis Obispo, CA 93401-3117 --- 805.784.9461 805.784.9462 (fax) [EMAIL PROTECTED] http://www.cdpubs.com -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/
RE: multi table relational databases
I've implemented a fairly simple relational database for an appliation. One problem with your suggested approach below is that it may be very tricky to sort the tables. Also, searches and inserts will take longer because they have to deal with a much larger Palm database. I used separate Palm databases for each table in the logical database. That way each table can have its own simple sort routine. Is there any particular reason why you don't want to create multiple Palm databases? -Bob Whiteman -Original Message- From: K. Chugh [mailto:[EMAIL PROTECTED]] Sent: Thursday, July 27, 2000 7:45 AM To: Palm Developer Forum Subject: multi table relational databases hi- i'm paranoid about introducing a new layer to my apps by using sybase ultralite, etc. does anyone know of any techniques for using multi table databases? i was thinking of opening one database and using the category for the table identifier then just inserting records in the appropriate "table." has anyone tried this? thanks, kevin -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/ -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/
Re: multi table relational databases
I programmed an app that uses 3 databases, and they're set up in a one to many relationship. It works great. I even have a delete which will work through the "sub databases" and delete useless records in them too. (Basically what a database is to plam, is what I consider a table... so if it's easier to think of it that way, do so.) I didn't have to use categories to do this. I just created a field in my 2 sub databases called ID which I stored the Unique ID of the previous record in each sub record created. This allows only certain records to be displayed if you want, and certain records to be deleted. Works like a charm ;-) + Timothy D. Astle Embedded Systems Programmer ALT Group Inc. + People on Jolt cola write the funniest things. A-10 Obedience Guide, Kitty Hawk Studios -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/
Re: multi table relational databases
hi bob. thanks for the reply. i am looking at like 14 or so tables, and i figured i don't want all those handles open at the same time. this is my first database program so i'm not sure if this is a rational concern or not. some of the tables will have only a few records, while others will have as many as a few thousand records. do you think i should actually implement one database for each table instead of one database with a table id? thanks, kevin Bob Whiteman wrote: I've implemented a fairly simple relational database for an appliation. One problem with your suggested approach below is that it may be very tricky to sort the tables. Also, searches and inserts will take longer because they have to deal with a much larger Palm database. I used separate Palm databases for each table in the logical database. That way each table can have its own simple sort routine. Is there any particular reason why you don't want to create multiple Palm databases? -Bob Whiteman -Original Message- From: K. Chugh [mailto:[EMAIL PROTECTED]] Sent: Thursday, July 27, 2000 7:45 AM To: Palm Developer Forum Subject: multi table relational databases hi- i'm paranoid about introducing a new layer to my apps by using sybase ultralite, etc. does anyone know of any techniques for using multi table databases? i was thinking of opening one database and using the category for the table identifier then just inserting records in the appropriate "table." has anyone tried this? thanks, kevin -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/ -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/ -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/
Re: multi table relational databases
What does having 14 Tables/DBs have to do with the Palm only having 16 categories? (really only 15 if you count the obligatory 'all' category). Category use is definable or ignoble by the programmer. To get around the # limitation, you just ignore the PDB built in category mechanism and use your own if need be. I've seen applications from other developers with essentially an unlimited # of categories. - Original Message - From: "Bob Whiteman" [EMAIL PROTECTED] To: "Palm Developer Forum" [EMAIL PROTECTED] Sent: Thursday, July 27, 2000 1:58 PM Subject: RE: multi table relational databases Well 14 tables raises a new concern. You can only have 16 categories in a Palm database. If you were to add a couple more tables to your already extensive database you'll be out of luck. -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/
