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by Zhu >> Mon, 26 Jan 2004 12:32:02 GMT

Hi , can anybody help me, when I remove Schema from Schema browser. It's always asking that "You are about to delete schema myproject ,Instances of all classes in this schema will also be deleted". and If continue , when reload Schema all the instances previously created are all gone. How can I can store data in my schema permanently?


Regards,

Zhu

by Patwos >> Mon, 26 Jan 2004 22:39:40 GMT

It may seem obvious, but don't delete your schema. By deleting your schema, and confirming the warning dialog, you are saying you no longer want that schema nor any of the instances of classes defined in that schema.

I guess the next question is why are you deleting your schema if you still want the data for that schema?

Hope that helps,
Pat.

PS: Happy New Year one and all.

by Zhu >> Tue, 27 Jan 2004 3:24:29 GMT

Thanks, Pat

Yea, my computer is slow,If I load many schemas, it will run very slowly and if I want to extract shema and use in other machines. Do I have to create instances everytime I reload the schema?

So, is it possible to keep datas in a schema permanently. I have a tutorial schema from" Learning JADE-A Three Part Course". The schema name BookingSchema and YouFinishitSchema (JADE TeleTicKets). I noticed that when the schema has been loaded,there are some datas already there. When I remove , it didn't show the warning dialog and when I reloaded the data still there.

by Torrie >> Tue, 27 Jan 2004 8:11:57 GMT

It is possible to extract all the data from a Jade system and then to reload it. The Jade dump and load utility supplied with Jade allows you to do this. The Dump process will extract ALL data from ALL schemas. It is a good idea that if you do dump the data, you extract the schemas and use the same schemas when you reload the data. The dumpload.hlp file contains the details of the process.

by cnwrbb1 >> Wed, 28 Jan 2004 21:02:29 GMT

A tehchnique that can be useful when developing something new is to have a DataGenerator class that, well, does exactly that. It may parse some input files, or it may create data from hardcoded values, but it means you can easily recreate simple test data that you can use as you develop a system. If you lose data integrity (forgot to set references, or deleted objects without inverses), then it's easier to purge and recreate the data than to fix it. Similarly if you load the code onto another PC, then you can easily recreate the data. The Erewhon example system uses this technique.

Cheers,
Rob

by Zhu >> Thu, 29 Jan 2004 7:40:02 GMT

Thanks for all responses.