=head1 Name

sqitch-revert - Revert changes to a database

=head1 Synopsis

  sqitch [options] revert [<database>]
  sqitch [options] revert [<database>] <change>
  sqitch [options] revert [<database>] --to-change <change>

=head1 Description

Revert changes to the database. Starting from the current deployment state,
changes will be reverted in reverse the order of application. All changes will
be reverted unless a change is specified, either via C<--to> or with no option
flag, in which case changes will be reverted back to that change.

If the database has not been deployed to, or its state already matches the
specified change, no changes will be made. If the change appears later in the
plan than the currently-deployed state, an error will be returned, along with
a suggestion to instead use L<sqitch-deploy>.

The C<< <database> >> parameter specifies the database to which to connect,
and may also be specified as the C<--target> option. It can be target name,
a URI, an engine name, or plan file path.

=head1 Options

=over

=item C<-t>

=item C<--target>

The target database to which to connect. This option can be either a URI or
the name of a target in the configuration.

=item C<--to-change>

=item C<--change>

=item C<--to>

Specify the reversion change. Defaults to reverting all changes. See
L<sqitchchanges> for the various ways in which changes can be specified.

=item C<-s>

=item C<--set>

Set a variable name and value for use by the database engine client, if it
supports variables. The format must be C<name=value>, e.g.,
C<--set defuser='Homer Simpson'>. Overrides any values loaded from the
C<deploy.variables> or C<revert.variables> configurations.

=item C<--log-only>

Log the changes as if they were reverted, but without actually running the
revert scripts.

=item C<-y>

Disable the prompt that normally asks whether or not to execute the revert.

=back

=head1 Configuration Variables

=over

=item C<[deploy.variables]>

=item C<[revert.variables]>

A section defining database client variables. The C<deploy.variables>
configuration is read from the C<deploy> command configuration, on the
assumption that the values will generally be the same. If they're not, use
C<revert.variables> to override C<deploy.variables>.

These variables are useful if your database engine supports variables in
scripts, such as PostgreSQL's
L<C<psql> variables|http://www.postgresql.org/docs/current/static/app-psql.html#APP-PSQL-INTERPOLATION>,
Vertica's
L<C<vsql> variables|http://my.vertica.com/docs/7.1.x/HTML/index.htm#Authoring/ConnectingToHPVertica/vsql/Variables.htm>,
MySQL's
L<user variables|http://dev.mysql.com/doc/refman/5.6/en/user-variables.html>,
and SQL*Plus's
L<C<DEFINE> variables|http://docs.oracle.com/cd/B19306_01/server.102/b14357/ch12017.htm>.

=item C<[revert.no_prompt]>

A boolean value indicating whether or not to disable the prompt before
executing the revert. My be overridden by C<-y>.

=item C<[revert.prompt_accept]>

A boolean value indicating whether default reply to the prompt before
executing the revert should be "yes" or "no". Defaults to true, meaning to
accept the revert.

=back

=head1 Sqitch

Part of the L<sqitch> suite.