Support Docs & Contrib

doc/man/fetch.l

@@ -0,0 +1,70 @@
+.\" This is -*-nroff-*-
+.\" XXX standard disclaimer belongs here....
+.\" $Header: /cvsroot/pgsql/doc/man/Attic/fetch.l,v 1.1.1.1 1996/08/18 22:14:24 scrappy Exp $
+.TH FETCH SQL 01/23/93 Postgres95 Postgres95
+.SH NAME
+fetch \(em fetch instance(s) from a cursor
+.SH SYNOPSIS
+.nf
+\fBfetch\fR [ (\fBforward\fR | \fBbackward\fR) ] [ ( number | \fBall\fR) ] [\fBin\fR cursor_name]
+.fi
+.SH DESCRIPTION
+.BR Fetch
+allows a user to retrieve instances from a cursor named
+.IR cursor_name.
+The number of instances retrieved is specified by
+.IR number .
+If the number of instances remaining in the cursor is less than
+.IR number ,
+then only those available are fetched.  Substituting the keyword
+.IR all
+in place of a number will cause all remaining instances in the cursor 
+to be retrieved.  Instances may be fetched in both
+.IR forward
+and
+.IR backward
+directions.  The default direction is
+.IR forward .
+.PP
+Updating data in a cursor is not supported by Postgres, because mapping
+cursor updates back to base classes is impossible in general as with
+view updates.  Consequently, users must issue explicit replace
+commands to update data.
+.PP
+Portals may only be used inside of transaction blocks marked by 
+.IR begin (l)
+and
+.IR end (l)
+because the data that they store spans multiple user queries.
+.SH EXAMPLE
+.nf
+--
+--set up and use a cursor 
+--
+begin 
+   declare myportal cursor for 
+   select * from pg-user
+end 
+.fi
+.nf
+--
+--Fetch all the instances available in the portal FOO
+--
+fetch all in FOO
+.fi
+.nf
+--
+--Fetch 5 instances backward in the portal FOO
+--
+fetch backward 5 in FOO
+.fi
+.SH "SEE ALSO"
+begin(l),
+end(l),
+close(l),
+move(l),
+select(l).
+.SH BUGS
+Currently, the smallest transaction in Postgres is a single SQL
+command.  It should be possible for a single fetch to be a
+transaction.