[rset] New method: ResultSet.one()
This method will return exactly one entity while enforcing its existence and unicity.
The idea is shamelessly borowed from SQLAlchemy Query.one().
Closes #3352314
[jcr: use len(self) instead of len(self.rows)]
.TH cubicweb\-ctl 1 "2010-01-14" cubicweb\-ctl
.SH NAME
.B cubicweb\-ctl
\- cubicweb control utility
.SH SYNOPSIS
.B cubicweb-ctl <command>
[
.I OPTIONS
] [
.I <command arguments>
]
.SH DESCRIPTION
.PP
CubicWeb utility to create and control instances, and more generally do all
cubicweb's related tasks you can have to do using the command line. Available
commands will depends on which part of the framework are installed.
.PP
Type
.B "cubicweb\-ctl <command> \fB\-\-help\fR"
for more information about a specific command.
.SH COPYRIGHT
Copyright (c) 2003-2010 LOGILAB S.A. (Paris, FRANCE).
http://www.logilab.fr/ -- mailto:contact@logilab.fr