On Wed, Mar 29, 2006 at 12:24:04AM +0200, SunWuKung wrote: > In article <20060328221109.GC75181@xxxxxxxxxxxxx>, jnasby@xxxxxxxxxxxxx > says... > > On Tue, Mar 28, 2006 at 09:28:12PM +0200, SunWuKung wrote: > > > This is going to be an amateur question... > > > > > > Could somebody explain me, or point me to a resource where I can find > > > out what is the recommended practice when a live db needs to be replaced > > > with a new version of it that has a slightly different structure? > > > > > > My first guess would be to create the empty new version of the db and > > > insert the data of the old one into it - adding and modifying it when > > > necessary, but I am not sure. > > > > > > What do you usually do in a situation like this? > > > > ALTER TABLE ... > > > > I know this is easy to do when the db is empty, but do you still suggest > this when there is data in the db : changing the structure of the old > version of the db to match the new one (obviously not on the live > server) and than try to modify the data in it to fit the structure eg. > there are two new columns that needs data? Depends on how much data you need to modify. For small tables, I stick with ALTER TABLE because it's a lot cleaner/easier. For larger tables, you might want to CREATE TABLE AS SELECT ..., or maybe copy out and copy back in. -- Jim C. Nasby, Sr. Engineering Consultant jnasby@xxxxxxxxxxxxx Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
