Thread: question about images
Hi all, I have a problem with understanding how BLOB's work in postgres. It seems as thoug I have to use COPY BINARY table (imagefield) FROM 'absolutepath+imagename' ; this ofcourse give the error ERROR: COPY BINARY: file signature not recognized so I have new went througt some doc's and found that some header has to be appended containing some info about number of instances and flags etc. NOW: Is there anyway I can deal with loading images from files into my database from within a pgplsql function, or do I have to hack some C code AND install c-functions as well, or even worse 8) do some scripting outside the database.... ??? Thankfull for any input, regards, DagG
Dag Gullberg <dag.gullberg@telia.com> writes: > I have a problem with understanding how BLOB's > work in postgres. It seems as thoug I have to use > COPY BINARY table (imagefield) FROM 'absolutepath+imagename' ; No, what you want is lo_import(). regards, tom lane
Tom Lane <tgl@sss.pgh.pa.us> writes: >Dag Gullberg <dag.gullberg@telia.com> writes: >> I have a problem with understanding how BLOB's >> work in postgres. It seems as thoug I have to use >> COPY BINARY table (imagefield) FROM 'absolutepath+imagename' ; > > >No, what you want is lo_import(). > > regards, tom lane > Thanks for the input - and you're right! And wrong! I first thought of it as a neccessity to have the db to render me all data in a ''select * from table where id=this_id;'' including image data. I had a problem with the fact that lo_export() deposit the data on the local fs - anti-constructive if you are trying to setup a highly distributed and scalable solution. So in that context you were wrong! Or so I thought... *But*, thinking about it - the solution is simple - use lo_import and lo_export as you suggest - and deposit the outdata in a directory available from a apache-server, serving only image transfers. I don't know about performance yet, but it is doable -have tested that. Voila - I'm done (?) Thanks, DagG
torsdagen den 24 juli 2003 16:06 skrev Tom Lane: > Dag Gullberg <dag.gullberg@telia.com> writes: > > I have a problem with understanding how BLOB's > > work in postgres. It seems as thoug I have to use > > COPY BINARY table (imagefield) FROM 'absolutepath+imagename' ; > > No, what you want is lo_import(). > > regards, tom lane Wanting to share the novice discovery of things that is well known to you buffs I now can say that my problems are very neatly solved by using the pgsql module in php (type lo_import() access). Anybody out there have a similar problem the postgres JDBC doc may help if you are going in that direction. If php and "native" postgress access is wanted, see (e.g.) http://se.php.net/manual/en/function.pg-lo-create.php All in a box, as it were ..... DagG