Hi Andre, simple objects can be stored easily in a BLOB field, TTree's are not simple objects as they can write many buffers to file and without these buffers a TTree is not complete. But for simple objects (or purely in memory TTrees) the recipe is something like: TH1F *myhist = new TH1F(...); TMessage mess(kMESS_OBJECT); mess.WriteObject(myhist); char *buf = mess.Buffer(); int len = mess.Length(); store "buf" with length "len" in DB. To read back retrieve BLOB in "buf" and length in "len" and do: TMessage mess(buf, len); TH1F *myhist = (TH1F*) mess.ReadObject(mess.GetClass()); Cheers, Fons. On Fri, 2002-03-08 at 15:52, André David wrote: > ps - My bottom line with TSQLServer is to understand if I can put a > TObject (TTree or TH*) directly in a BLOB field of the DB. Any > experience/answer/hint to this end is very welcome. -- Org: CERN, European Laboratory for Particle Physics. Mail: 1211 Geneve 23, Switzerland E-Mail: Fons.Rademakers@cern.ch Phone: +41 22 7679248 WWW: http://root.cern.ch/~rdm/ Fax: +41 22 7679480
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