=head1 Name

sqitch-deploy - Deploy changes to a database

=head1 Synopsis

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

=head1 Description

Deploy changes to the database. Changes will begin from the current deployment
state. They will run to the latest change, unless a change is specified,
either via C<--to> or with no option flag, in which case changes will be
deployed up-to and including that change.

If the database it up-to-date or already deployed to the specified change, no
changes will be made. If the change appears earlier in the plan than the
currently-deployed state, an error will be returned, along with a suggestion
to instead use L<sqitch-revert>.

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 deployment change. Defaults to the last point in the plan. See
L<sqitchchanges> for the various ways in which changes can be specified.

=item C<--mode>

Specify the reversion mode to use in case of deploy or verify failure.
Possible values are:

=over

=item C<all>

In the event of failure, revert all deployed changes, back to the point at
which deployment started. This is the default.

=item C<tag>

In the event of failure, revert all deployed changes to the last
successfully-applied tag. If no tags were applied during this deployment, all
changes will be reverted to the point at which deployment began.

=item C<change>

In the event of deploy failure, no changes will be reverted; for a verify
failure, only the failed change will be reverted.

=back

Note that Sqitch assumes that each change is atomic. Therefore, when a deploy
script fails, it assumes there is nothing to revert. If a verify script fails,
it will of course run the revert script for the failed change.

=item C<--verify>

Verify each change by running its verify script, if there is one. If a verify
test fails, the deploy will be considered to have failed and the appropriate
reversion will be carried out, depending on the value of C<--mode>.

=item C<--no-verify>

Don't verify each change. This is the default.

=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
L</configuration Variables>.

=item C<--log-only>

Log the changes as if they were deployed, but without actually running the
deploy scripts. Useful for an existing database that is being converted to
Sqitch, and you need to log changes as deployed because they have been
deployed by other means in the past.

=item C<--registry>

  sqitch deploy --registry registry

The name of the Sqitch registry schema or database in which sqitch stores its
own data.

=item C<--db-client>

=item C<--client>

  sqitch deploy --client /usr/local/pgsql/bin/psql

Path to the command-line client for the database engine. Defaults to a client
in the current path named appropriately for the database engine.

=item C<-d>

=item C<--db-name>

  sqitch deploy --db-name widgets
  sqitch deploy -d bricolage

Name of the database. In general, L<targets|sqitch-target> and URIs are
preferred, but this option can be used to override the database name in a
target.

=item C<-u>

=item C<--db-user>

=item C<--db-username>

  sqitch deploy --db-username root
  sqitch deploy --db-user postgres
  sqitch deploy -u Mom

User name to use when connecting to the database. Does not apply to all
engines. In general, L<targets|sqitch-target> and URIs are preferred, but this
option can be used to override the user name in a target.

=item C<-h>

=item C<--db-host>

  sqitch deploy --db-host db.example.com
  sqitch deploy -h appdb.example.net

Host name to use when connecting to the database. Does not apply to all
engines. In general, L<targets|sqitch-target> and URIs are preferred, but this
option can be used to override the host name in a target.

=item C<-p>

=item C<--db-port>

  sqitch deploy --db-port 7654
  sqitch deploy -p 5431

Port number to connect to. Does not apply to all engines. In general,
L<targets|sqitch-target> and URIs are preferred, but this option can be used
to override the port in a target.

=item C<--plan-file>

=item C<-f>

  sqitch deploy --plan-file my.plan

Path to the deployment plan file. Overrides target, engine, and core
configuration values. Defaults to F<$top_dir/sqitch.plan>.

=back

=head1 Configuration Variables

=over

=item C<deploy.mode>

Deploy mode. The supported values are the same as for the C<--mode> option.

=item C<deploy.verify>

Boolean indicating whether or not to verify each change.

=item C<[deploy.variables]>

A section defining database client variables. Useful if your database engine
supports variables in scripts, such as PostgreSQL's
L<C<psql> variables|https://www.postgresql.org/docs/current/static/app-psql.html#APP-PSQL-INTERPOLATION>,
Vertica's
L<C<vsql> variables|https://my.vertica.com/docs/7.1.x/HTML/index.htm#Authoring/ConnectingToHPVertica/vsql/Variables.htm>
MySQL's
L<user variables|https://dev.mysql.com/doc/refman/5.6/en/user-variables.html>,
SQL*Plus's
L<C<DEFINE> variables|https://docs.oracle.com/cd/B19306_01/server.102/b14357/ch12017.htm>,
and Snowflake's
L<SnowSQL variables|https://docs.snowflake.net/manuals/user-guide/snowsql-use.html#using-variables>.

May be overridden by C<--set> or target and engine configuration. Variables
are merged in the following priority order:

=over

=item C<--set>

=item C<target.$target.variables>

=item C<engine.$engine.variables>

=item C<deploy.variables>

=item C<core.variables>

=back

=back

=head1 Sqitch

Part of the L<sqitch> suite.