Re: pg_get_tabledef - Mailing list pgsql-hackers

I think using pg_dump in some cases is a good option , but not all the time, having a function makes it much cleaner
touse<br /><br /> Consider pgAdmin lets say (and there are many such applications out there) , you need to show object
DDLon the RHP and its nicely formatted and you can copy paste it and then perhaps export it in an SQL file.<br /><br />
Nowimagine you need to spawn a new process from inside the app for pg_dump, and then make it write to a file and then
readthe file to display the object DDL, which is possible but very messy looking code. Then there are issues with
launchingexternal processes on certain platforms (for example in Java if you start a new process from the runtime(),
youneed to make sure you properly flush out its stdout and stderr streams otherwise it can go in a deadlock etc), i
woulduse a function, if available anyday <br /><br /> Additionally  there are such functions for other objects, but for
tablesyou needed to construct it manually, so i also thought this would just complete the set and make it easier to
writean SQL / DDL exporting app.<br /><br /><br /><br /> Naz Gassiep wrote: <blockquote
cite="mid4651B51F.3000908@mira.net"type="cite"><pre wrap="">Just a question, is there any advantage to having this then
buildinga
 
function in applications that wrap and use pg_dump with a few options?
Surely that's a more appropriate way to achieve this functionality?
- Naz.


Usama Munir wrote: </pre><blockquote type="cite"><pre wrap="">Hi,

i was following a thread some time ago where adding a function
*pg_get_tabledef* was one of the TODOs for 8.2, but it somehow didn't
make it to the release perhaps because the functionality was not
clearly defined? not sure.

Anyway  i happen to come up with a function for pg_get_tabledef which
works something like following

/postgres=# select pg_get_tabledef(16388) ;       pg_get_tabledef        
--------------------------------CREATE TABLE  public.dept( deptno numeric(2,0) NOT NULL, dname  character varying(14),
loc   character varying(13))WITHOUT OIDS;
 
/(1 row)



i wanted to submit a patch for this, IFF the community wants this
function. The rationale is obviously to help Application developers
writing applications like pgAdmin. Currently this part of SQL needs to
be constructed manually for postgres by the tools.

it is arguable that a table defintion will have constraints , triggers
etc as well, and they can be added without much problem, but i think
if a tool needs to construct an SQL for all table related objects then
functions are already available for them like pg_get_constraintdef,
pg_get_ruledef, pg_get_indexdef, pg_get_triggerdef etc

i understand that you guys don't like someone to develop a patch in
isolation and just come up with it one day, but it really came out as
a by-product of some other work , and i thought you guys might be
interested in it.

if it is desired,  i will submit  a patch for it, within a day or so.

Regards,
Usama Munir
EnterpriseDB (<a class="moz-txt-link-abbreviated" href="http://www.enterprisedb.com">www.enterprisedb.com</a>)


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