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=encoding UTF-8
=head1 Name
sqitchtutorial-oracle - A tutorial introduction to Sqitch change management on Oracle
=head1 Synopsis
sqitch *
=head1 Description
This tutorial explains how to create a sqitch-enabled Oracle project, use a
VCS for deployment planning, and work with other developers to make sure
changes remain in sync and in the proper order.
We'll start by creating new project from scratch, a fictional antisocial
networking site called Flipr. All examples use L<Git|https://git-scm.com/> as
the VCS and L<Oracle|https://www.oracle.com/us/products/database/> as the
storage engine. Note that you will need to set
L<C<$ORACLE_HOME>|https://www.orafaq.com/wiki/ORACLE_HOME> so that all the
database connections will work.
If you'd like to manage a PostgreSQL database, see L<sqitchtutorial>.
If you'd like to manage an SQLite database, see L<sqitchtutorial-sqlite>.
If you'd like to manage a MySQL database, see L<sqitchtutorial-mysql>.
If you'd like to manage a Firebird database, see L<sqitchtutorial-firebird>.
If you'd like to manage a Vertica database, see L<sqitchtutorial-vertica>.
If you'd like to manage an Exasol database, see L<sqitchtutorial-exasol>.
If you'd like to manage a Snowflake database, see L<sqitchtutorial-snowflake>.
=head2 Prerequisites
Sqitch requires L<Oracle Instant Client|https://www.oracle.com/database/technologies/instant-client.html>
and the L<DBD::Oracle> Perl module to manage Oracle databases. Skip this section
if you already have them installed and configured.
=head3 Instant Client
Sqitch requires three Instant Client packages:
=over
=item 1.
Instant Client Basic
=item 2.
Instant Client SQL*Plus
=item 3.
Instant Client SDK
=back
Download all three as appropriate for your platform and OS, unpack them and
put them all in a single directory, such as F<instantclient> in your home
directory. Then set the C<$ORACLE_HOME> environment variable to that directory
and add it to the path the PATH and LD_LIBRARY_PATH variables. For example:
export ORACLE_HOME=$HOME/instantclient
export PATH=$ORACLE_HOME:$PATH
export LD_LIBRARY_PATH=$ORACLE_HOME
=head3 DBD::Oracle
With these variables in place, install DBD::Oracle, like so:
cpanm DBD::Oracle
If you run into issues, consult L<DBD::Oracle::Troubleshooting> and the
relevant platform-specific C<DBD::Oracle::Troubleshooting::*> guides
L<listed here|https://metacpan.org/dist/DBD-Oracle>.
=head2 Test Environment
If you have an Oracle instance ready to hand, you can skip this section. For
For those who don't have a handy Oracle instance lying around, try using one
of the L<Oracle-XE Docker images|https://hub.docker.com/r/gvenzl/oracle-xe>
or the L<Database Virtual Box Appliance|https://www.oracle.com/database/technologies/databaseappdev-vm.html>.
Details on each follow.
=head3 Oracle-XE Docker Configuration
The simplest way to the Sqitch Oracle engine is with the
[gvenzl/oracle-xe](https://hub.docker.com/r/gvenzl/oracle-xe) docker image.
Essentially, start it like so:
docker run -d -p 1521:1521 \
-e ORACLE_PASSWORD=oracle \
-e APP_USER=scott \
-e APP_USER_PASSWORD=tiger \
gvenzl/oracle-xe:18-slim
This will create a user (and schema) named C<scott> in the pluggable database C<pdb1>.
To create a SID named C<flipr_test> pointing to the C<pdb1> database, add this entry to
F<$ORACLE_HOME/network/admin/tnsnames.ora>:
FLIPR_TEST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = pdb1)
)
)
=head3 Virtual Box Configuration
Some instructions for setting up the Database Virtual Box Appliance for
following along in this tutorial.
=over
=item *
See F<t/oracle.t> for instructions on downloading, installing, and configuring
the Oracle developer days VM.
=item *
Download and install L<VirtualBox|https://www.virtualbox.org/wiki/Downloads>.
=item *
Download the VM from the L<Database Virtual Box
Appliance|https://www.oracle.com/database/technologies/databaseappdev-vm.html>
page and import it into VirtualBox.
=item *
Once the VM is imported into VirtualBox and started, login with the username
"oracle" and the password "oracle". Then, in VirtualBox, go to Settings ->
Network, select the NAT adapter, and add two port forwarding rules
(https://barrymcgillin.blogspot.com/2011/12/using-oracle-developer-days-virtualbox.html):
Host Port | Guest Port
-----------+------------
1521 | 1521
2222 | 22
Then restart the VM. You should then be able to connect from your host with:
sqlplus sys/oracle@localhost/ORCL as sysdba
If this fails with either of these errors:
ORA-01017: invalid username/password; logon denied ORA-21561: OID
generation failed
Make sure that your computer's hostname is on the localhost line of F</etc/hosts>
(L<reference|https://sourceforge.net/p/tora/discussion/52737/thread/f68b89ad/>):
> hostname
stickywicket
> grep 127 /etc/hosts
127.0.0.1 localhost stickywicket
=item *
Give user C<scott> the access it needs:
ALTER USER scott IDENTIFIED BY tiger;
GRANT ALL PRIVILEGES TO scott;
=item *
To create a SID named C<flipr_test> pointing to the C<pdb1> database, add this entry to
F<$ORACLE_HOME/network/admin/tnsnames.ora>:
FLIPR_TEST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(CONNECT_DATA =
(SERVER = DEDICATED)
(SERVICE_NAME = orcl)
)
)
=back
=head1 Starting a New Project
Usually the first thing to do when starting a new project is to create a
source code repository. So let's do that with Git:
> mkdir flipr
> cd flipr
> git init .
Initialized empty Git repository in /flipr/.git/
> touch README.md
> git add .
> git commit -am 'Initialize project, add README.'
[main (root-commit) 1bd134b] Initialize project, add README.
1 file changed, 38 insertions(+)
create mode 100644 README.md
If you're a Git user and want to follow along the history, the repository used
in these examples is L<on GitHub|https://github.com/sqitchers/sqitch-oracle-intro>.
Now that we have a repository, let's get started with Sqitch. Every Sqitch
project must have a name associated with it, and, optionally, a unique URI. We
recommend including the URI, as it increases the uniqueness of object
identifiers internally, so let's specify one when we initialize Sqitch:
identifiers internally, and will prevent the deployment of a different project
with the same name. So let's specify one when we initialize Sqitch:
Created sqitch.conf
Created sqitch.plan
Created deploy/
Created revert/
Created verify/
Let's have a look at F<sqitch.conf>:
> cat sqitch.conf
[core]
engine = oracle
# plan_file = sqitch.plan
# top_dir = .
# [engine "oracle"]
# target = db:oracle:
# registry =
# client = sqlplus
Good, it picked up on the fact that we're creating changes for the Oracle
engine, thanks to the C<--engine oracle> option, and saved it to the file.
Furthermore, it wrote a commented-out C<[engine "oracle"]> section with all
the available Oracle engine-specific settings commented out and ready to be
edited as appropriate. This includes the path to
L<SQL*Plus|https://www.orafaq.com/wiki/SQL*Plus> in my C<$ORACLE_HOME>.
By default, Sqitch will read F<sqitch.conf> in the current directory for
settings. But it will also read F<~/.sqitch/sqitch.conf> for user-specific
settings. Let's tell it who we are, since this data will be used in all of our
projects:
> sqitch config --user user.name 'Marge N. O’Vera'
> sqitch config --user user.email 'marge@example.com'
Have a look at F<~/.sqitch/sqitch.conf> and you'll see this:
> cat ~/.sqitch/sqitch.conf
[user]
name = Marge N. O’Vera
email = marge@example.com
Which means that Sqitch will always properly identify us when planning and
committing changes. Back to the repository. Have a look at the plan file,
F<sqitch.plan>:
> cat sqitch.plan
%syntax-version=1.0.0
%project=flipr
%uri=https://github.com/sqitchers/sqitch-oracle-intro/
Note that it has picked up on the name and URI of the app we're building.
Sqitch uses this data to manage cross-project dependencies. The
C<%syntax-version> pragma is always set by Sqitch, so that it always knows how
to parse the plan, even if the format changes in the future.
Let's commit these changes and start creating the database changes.
> git add .
> git commit -am 'Initialize Sqitch configuration.'
[main bd82f41] Initialize Sqitch configuration.
2 files changed, 19 insertions(+)
create mode 100644 sqitch.conf
create mode 100644 sqitch.plan
=head1 Our First Change
First, our project will need an Oracle user and accompanying schema. This
creates a nice namespace for all of the objects that will be part of the flipr
app. Run this command:
> sqitch add appschema -n 'App user and schema for all flipr objects.'
Created deploy/appschema.sql
Created revert/appschema.sql
Created verify/appschema.sql
Added "appschema" to sqitch.plan
The L<C<add>|sqitch-add> command adds a database change to the plan and writes
deploy, revert, and verify scripts that represent the change. Now we edit
these files. The C<deploy> script's job is to create the user. So we add
this to F<deploy/appschema.sql>:
CREATE USER flipr IDENTIFIED BY whatever;
The C<revert> script's job is to precisely revert the change to the deploy
script, so we add this to F<revert/appschema.sql>:
DROP USER flipr;
Now we can try deploying this change. Before going any further, unless you're
using the Docker or VM environments described above, you might need to
L<create the database|https://docs.oracle.com/cd/B28359_01/server.111/b28310/create001.htm#ADMIN11068>
and configure the SID. Assuming you have an Oracle SID named C<FLIPR_TEST> set
up in your C<F<TNSNAMES.ORA>|https://www.orafaq.com/wiki/Tnsnames.ora> file,
tell Sqitch where to send the change via a
L<database URI|https://github.com/libwww-perl/uri-db/>, such as
export SQITCH_URI=db:oracle://$username:$password@/flipr_test
With that URI set up, we can deploy:
> sqitch deploy db:oracle://scott:tiger@/flipr_test
Adding registry tables to db:oracle://scott:@/flipr_test
Deploying changes to db:oracle://scott:@/flipr_test
+ appschema .. ok
First Sqitch created the registry tables used to track database changes. The
structure and name of the registry varies between databases, but in Oracle
they are simply stored in the current schema -- that is, the schema with the
same name as the user you've connected as. In this example, that schema is
C<scott>. Ideally, only Sqitch data will be stored in this schema, so it
probably makes the most sense to create a superuser named C<sqitch> or
something similar and use it to deploy changes.
If you'd like it to use a different database as the registry database, use
C<sqitch engine add oracle $name> to configure it (or via the
L<C<target> command|sqitch-target>; more L<below|/On Target>). This will be
useful if you don't want to use the same registry database to manage multiple
databases on the same server.
Next, Sqitch deploys changes to the target database, which we specified on the
command-line. We only have one change so far; the C<+> reinforces the idea
that the change is being I<added> to the database.
With this change deployed, if you connect to the database, you'll be able to
see the schema:
> echo "SELECT username FROM all_users WHERE username = 'FLIPR';" \
| sqlplus -S scott/tiger@flipr_test
USERNAME
------------------------------
FLIPR
=head2 Trust, But Verify
But that's too much work. Do you really want to do something like that after
every deploy?
Here's where the C<verify> script comes in. Its job is to test that the deploy
did was it was supposed to. It should do so without regard to any data that
might be in the database, and should throw an error if the deploy was not
successful. In Oracle, the simplest way to do so for schema is probably to
simply create an object in the schema. Put this SQL into
F<verify/appschema.sql>:
CREATE TABLE flipr.verify__ (id int);
DROP TABLE flipr.verify__;
In truth, you can use I<any> query that generates an SQL error if the schema
doesn't exist. This works because Sqitch configures SQL*Plus so that SQL
errors cause it to exit with the error code (more on that below). Another
handy way to do that is to divide by zero if an object doesn't exist. For
example, to throw an error when the C<flipr> schema does not exist, you could
do something like this:
SELECT 1/COUNT(*) FROM sys.all_users WHERE username = 'FLIPR';
Either way, run the C<verify> script with the L<C<verify>|sqitch-verify>
command:
> sqitch verify db:oracle://scott:tiger@/flipr_test
Verifying db:oracle://scott:@/flipr_test
* appschema .. ok
Verify successful
Looks good! If you want to make sure that the verify script correctly dies if
the schema doesn't exist, temporarily change the schema name in the script to
something that doesn't exist, something like:
CREATE TABLE nonesuch.verify__ (id int);
Then L<C<verify>|sqitch-verify> again:
> sqitch verify db:oracle://scott:tiger@/flipr_test
Verifying db:oracle://scott:@/flipr_test
* appschema .. CREATE TABLE nonesuch.verify__ (id int)
*
ERROR at line 1:
ORA-01918: user 'NONESUCH' does not exist
# Verify script "verify/appschema.sql" failed.
not ok
Verify Summary Report
---------------------
Changes: 1
Errors: 1
Verify failed
It's even nice enough to tell us what the problem is. Or, for the
divide-by-zero example, change the schema name:
SELECT 1/COUNT(*) FROM sys.all_users WHERE username = 'NONESUCH';
Then the verify will look something like:
> sqitch verify db:oracle://scott:tiger@/flipr_test
Verifying db:oracle://scott:@/flipr_test
* appschema .. SELECT 1/COUNT(*) FROM sys.all_users WHERE username = 'NONESUCH'
*
ERROR at line 1:
ORA-01476: divisor is equal to zero
# Verify script "verify/appschema.sql" failed.
not ok
Verify Summary Report
---------------------
Changes: 1
Errors: 1
Verify failed
Less useful error output, but enough to alert us that something has gone
wrong.
Don't forget to change the schema name back before continuing!
=head2 Status, Revert, Log, Repeat
For purely informational purposes, we can always see how a deployment was
recorded via the L<C<status>|sqitch-status> command, which reads the registry
tables from the database:
> sqitch status db:oracle://scott:tiger@/flipr_test
# On database db:oracle://scott:@/flipr_test
# Project: flipr
# Change: c59e700589fc03568e8f35f592c0d9b7c638cbdd
# Name: appschema
# Deployed: 2013-12-31 15:25:23 -0800
# By: Marge N. O’Vera <marge@example.com>
#
Nothing to deploy (up-to-date)
Let's make sure that we can revert the change:
> sqitch revert db:oracle://scott:tiger@/flipr_test
Revert all changes from db:oracle://scott:@/flipr_test? [Yes]
- appschema .. ok
The L<C<revert>|sqitch-revert> command first prompts to make sure that we
really do want to revert. This is to prevent unnecessary accidents. You can
pass the C<-y> option to disable the prompt. Also, notice the C<-> before the
change name in the output, which reinforces that the change is being
I<removed> from the database. And now the schema should be gone:
> echo "SELECT username FROM all_users WHERE username = 'FLIPR';" \
| sqlplus -S scott/tiger@flipr_test
no rows selected
And the status message should reflect as much:
> sqitch status db:oracle://scott:tiger@/flipr_test
# On database db:oracle://scott:@/flipr_test
No changes deployed
Of course, since nothing is deployed, the L<C<verify>|sqitch-verify> command
has nothing to verify:
> sqitch verify db:oracle://scott:tiger@/flipr_test
Verifying db:oracle://scott:@/flipr_test
No changes deployed
However, we still have a record that the change happened, visible via the
L<C<log>|sqitch-log> command:
> sqitch log db:oracle://scott:tiger@/flipr_test
On database db:oracle://scott:@/flipr_test
Revert c59e700589fc03568e8f35f592c0d9b7c638cbdd
Name: appschema
Committer: Marge N. O’Vera <marge@example.com>
Date: 2013-12-31 16:19:38 -0800
App user and schema for all flipr objects.
Deploy c59e700589fc03568e8f35f592c0d9b7c638cbdd
Name: appschema
Committer: Marge N. O’Vera <marge@example.com>
Date: 2013-12-31 15:25:23 -0800
App user and schema for all flipr objects.
Note that the actions we took are shown in reverse chronological order, with
the revert first and then the deploy.
Cool. Now let's commit it.
> git add .
> git commit -m 'Add flipr schema.'
[main e0e0b11] Add flipr schema.
4 files changed, 11 insertions(+)
create mode 100644 deploy/appschema.sql
create mode 100644 revert/appschema.sql
create mode 100644 verify/appschema.sql
And then deploy again. This time, let's use the C<--verify> option, so that
the C<verify> script is applied when the change is deployed:
> sqitch deploy --verify db:oracle://scott:tiger@/flipr_test
Deploying changes to db:oracle://scott:@/flipr_test
+ appschema .. ok
And now the schema should be back:
> echo "SELECT username FROM all_users WHERE username = 'FLIPR';" \
| sqlplus -S scott/tiger@flipr_test
USERNAME
------------------------------
FLIPR
When we look at the status, the deployment will be there:
> sqitch status db:oracle://scott:tiger@/flipr_test
# On database db:oracle://scott:@/flipr_test
# Project: flipr
# Change: c59e700589fc03568e8f35f592c0d9b7c638cbdd
# Name: appschema
# Deployed: 2013-12-31 16:22:01 -0800
# By: Marge N. O’Vera <marge@example.com>
#
Nothing to deploy (up-to-date)
=head1 On Target
I'm getting a little tired of always having to type
C<db:oracle://scott:tiger@/flipr_test>, aren't you? This
L<database connection URI|https://github.com/libwww-perl/uri-db/> tells Sqitch how
to connect to the deployment target, but we don't have to keep using the URI.
We can name the target:
> sqitch target add flipr_test db:oracle://scott:tiger@/flipr_test
The L<C<target>|sqitch-target> command, inspired by
L<C<git-remote>|https://git-scm.com/docs/git-remote>, allows management of one
or more named deployment targets. We've just added a target named
C<flipr_test>, which means we can use the string C<flipr_test> for the target,
rather than the URI. But since we're doing so much testing, we can also tell
Sqitch to deploy to the C<flipr_test> target by default:
> sqitch engine add oracle flipr_test
Now we can omit the target argument altogether, unless we need to deploy to
another database. Which we will, eventually, but at least our examples will be
simpler from here on in, e.g.:
> sqitch status
# On database flipr_test
# Project: flipr
# Change: c59e700589fc03568e8f35f592c0d9b7c638cbdd
# Name: appschema
# Deployed: 2013-12-31 16:22:01 -0800
# By: Marge N. O’Vera <marge@example.com>
#
Nothing to deploy (up-to-date)
Yay, that allows things to be a little more concise. Let's also make sure that
changes are verified after deploying them:
> sqitch config --bool deploy.verify true
> sqitch config --bool rebase.verify true
We'll see the L<C<rebase>|sqitch-rebase> command a bit later. In the meantime,
let's commit the new configuration and make some more changes!
> git commit -am 'Set default target and always verify.'
[main c4a308a] Set default target and always verify.
1 file changed, 8 insertions(+)
=head1 Deploy with Dependency
Let's add another change, this time to create a table. Our app will need
users, of course, so we'll create a table for them. First, add the new change:
> sqitch add users --requires appschema -n 'Creates table to track our users.'
Created deploy/users.sql
Created revert/users.sql
Created verify/users.sql
Added "users [appschema]" to sqitch.plan
Note that we're requiring the C<appschema> change as a dependency of the new
C<users> change. Although that change has already been added to the plan and
therefore should always be applied before the C<users> change, it's a good
idea to be explicit about dependencies.
Now edit the scripts. When you're done, F<deploy/users.sql> should look like
this:
-- Deploy flipr:users to oracle
-- requires: appschema
CREATE TABLE flipr.users (
nickname VARCHAR2(512 CHAR) PRIMARY KEY,
password VARCHAR2(512 CHAR) NOT NULL,
timestamp TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP NOT NULL
);
A few things to notice here. On the second line, the dependence on the
C<appschema> change has been listed in a comment. This doesn't do anything,
but the default Oracle C<deploy> template lists it here for your reference
while editing the file. Useful, right?
The table itself will been created in the C<flipr> schema. This is why we need
to require the C<appschema> change.
Notice that we've done nothing about error handling. Sqitch needs SQL*Plus
to return failure when a script experiences an error, so one might expect that
each script would need to start with lines like these:
WHENEVER OSERROR EXIT 9
WHENEVER SQLERROR EXIT SQL.SQLCODE
However, Sqitch always sets these error handling parameters before it executes
your scripts, so you don't have to.
Now for the verify script. The simplest way to check that the table was
created and has the expected columns without touching the data? Just select
from the table with a false C<WHERE> clause. Add this to F<verify/users.sql>:
SELECT nickname, password, timestamp
FROM flipr.users
WHERE 0 = 1;
Now for the revert script: all we have to do is drop the table. Add this to
F<revert/users.sql>:
DROP TABLE flipr.users;
Couldn't be much simpler, right? Let's deploy this bad boy:
> sqitch deploy
Deploying changes to flipr_test
+ users .. ok
We know, since verification is enabled, that the table must have been created.
But for the purposes of visibility, let's have a quick look:
> echo "DESCRIBE flipr.users;" | sqlplus -S scott/tiger@flipr_test
Name Null? Type
----------------------------------------- -------- ----------------------------
NICKNAME NOT NULL VARCHAR2(512 CHAR)
PASSWORD NOT NULL VARCHAR2(512 CHAR)
TIMESTAMP NOT NULL TIMESTAMP(6) WITH TIME ZONE
We can also verify all currently deployed changes with the
L<C<verify>|sqitch-verify> command:
> sqitch verify
Verifying flipr_test
* appschema .. ok
* users ...... ok
Verify successful
Now have a look at the status:
> sqitch status
# On database flipr_test
# Project: flipr
# Change: 6840dc13beb0cd716b8bd3979b03a259c1e94405
# Name: users
# Deployed: 2013-12-31 16:32:31 -0800
# By: Marge N. O’Vera <marge@example.com>
#
Nothing to deploy (up-to-date)
Success! Let's make sure we can revert the change, as well:
> sqitch revert --to @HEAD^ -y
Reverting changes to appschema from flipr_test
- users .. ok
Note that we've used the C<--to> option to specify the change to revert to.
And what do we revert to? The symbolic tag C<@HEAD>, when passed to
L<C<revert>|sqitch-revert>, always refers to the last change deployed to the
database. (For other commands, it refers to the last change in the plan.)
Appending the caret (C<^>) tells Sqitch to select the change I<prior> to the
last deployed change. So we revert to C<appschema>, the penultimate change.
The other potentially useful symbolic tag is C<@ROOT>, which refers to the
first change deployed to the database (or in the plan, depending on the
command).
Back to the database. The C<users> table should be gone but the C<flipr> schema
should still be around:
> echo "DESCRIBE flipr.users;" | sqlplus -S scott/tiger@flipr_test
ERROR:
ORA-04043: object flipr.users does not exist
The L<C<status>|sqitch-status> command politely informs us that we have
undeployed changes:
> sqitch status
# On database flipr_test
# Project: flipr
# Change: c59e700589fc03568e8f35f592c0d9b7c638cbdd
# Name: appschema
# Deployed: 2013-12-31 16:22:01 -0800
# By: Marge N. O’Vera <marge@example.com>
#
Undeployed change:
* users
As does the L<C<verify>|sqitch-verify> command:
> sqitch verify
Verifying flipr_test
* appschema .. ok
Undeployed change:
* users
Verify successful
Note that the verify is successful, because all currently-deployed changes are
verified. The list of undeployed changes (just "users" here) reminds us about
the current state.
Okay, let's commit and deploy again:
> git add .
> git commit -am 'Add users table.'
[main 2506312] Add users table.
4 files changed, 17 insertions(+)
create mode 100644 deploy/users.sql
create mode 100644 revert/users.sql
create mode 100644 verify/users.sql
> sqitch deploy
Deploying changes to flipr_test
+ users .. ok
Looks good. Check the status:
> sqitch status
# On database flipr_test
# Project: flipr
# Change: 6840dc13beb0cd716b8bd3979b03a259c1e94405
# Name: users
# Deployed: 2013-12-31 16:34:28 -0800
# By: Marge N. O’Vera <marge@example.com>
#
Nothing to deploy (up-to-date)
Excellent. Let's do some more!
=head1 Add Two at Once
Let's add a couple more changes to add functions for managing users.
> sqitch add insert_user --requires users --requires appschema \
-n 'Creates a function to insert a user.'
Created deploy/insert_user.sql
Created revert/insert_user.sql
Created verify/insert_user.sql
Added "insert_user [users appschema]" to sqitch.plan
> sqitch add change_pass --requires users --requires appschema \
-n 'Creates a function to change a user password.'
Created deploy/change_pass.sql
Created revert/change_pass.sql
Created verify/change_pass.sql
Added "change_pass [users appschema]" to sqitch.plan
Now might be a good time to have a look at the deployment plan:
> cat sqitch.plan
%syntax-version=1.0.0
%project=flipr
%uri=https://github.com/sqitchers/sqitch-oracle-intro/
appschema 2013-12-31T22:34:42Z Marge N. O’Vera <marge@example.com> # App user and schema for all flipr objects.
users [appschema] 2014-01-01T00:31:20Z Marge N. O’Vera <marge@example.com> # Creates table to track our users.
insert_user [users appschema] 2014-01-01T00:35:21Z Marge N. O’Vera <marge@example.com> # Creates a function to insert a user.
change_pass [users appschema] 2014-01-01T00:35:28Z Marge N. O’Vera <marge@example.com> # Creates a function to change a user password.
Each change appears on a single line with the name of the change, a bracketed
list of dependencies, a timestamp, the name and email address of the user who
planned the change, and a note.
Let's write the code for the new changes. Here's what
F<deploy/insert_user.sql> should look like:
-- Deploy flipr:insert_user to oracle
-- requires: users
-- requires: appschema
CREATE OR REPLACE PROCEDURE flipr.insert_user(
nickname VARCHAR2,
password VARCHAR2
) AS
BEGIN
INSERT INTO flipr.users VALUES(
nickname,
LOWER( RAWTOHEX( UTL_RAW.CAST_TO_RAW(
sys.dbms_obfuscation_toolkit.md5(input_string => password)
) ) ),
DEFAULT
);
END;
/
SHOW ERRORS;
-- Drop and die on error.
DECLARE
l_err_count INTEGER;
BEGIN
SELECT COUNT(*)
INTO l_err_count
FROM all_errors
WHERE owner = 'FLIPR'
AND name = 'INSERT_USER';
IF l_err_count > 0 THEN
EXECUTE IMMEDIATE 'DROP PROCEDURE flipr.insert_user';
raise_application_error(-20001, 'Errors in FLIPR.INSERT_USER');
END IF;
END;
/
The C<DECLARE> PL/SQL block is to catch compilation warnings, which are not
normally fatal. It's admittedly
L<a bit convoluted|https://stackoverflow.com/a/16429231/79202>, but ensures that
errors propagate and a broken function get dropped.
Here's what F<verify/insert_user.sql> might look like:
-- Verify flipr:insert_user on oracle
DESCRIBE flipr.insert_user;
We simply take advantage of the fact that C<DESCRIBE> throws an exception if
the specified function does not exist.
And F<revert/insert_user.sql> should look something like this:
-- Revert flipr:insert_user from oracle
DROP PROCEDURE flipr.insert_user;
Now for C<change_pass>; F<deploy/change_pass.sql> might look like this:
-- Deploy flipr:change_pass to oracle
-- requires: users
-- requires: appschema
CREATE OR REPLACE PROCEDURE flipr.change_pass(
nick VARCHAR2,
oldpass VARCHAR2,
newpass VARCHAR2
) IS
flipr_auth_failed EXCEPTION;
BEGIN
UPDATE flipr.users
SET password = LOWER( RAWTOHEX( UTL_RAW.CAST_TO_RAW(
sys.dbms_obfuscation_toolkit.md5(input_string => newpass)
) ) )
WHERE nickname = nick
AND password = LOWER( RAWTOHEX( UTL_RAW.CAST_TO_RAW(
sys.dbms_obfuscation_toolkit.md5(input_string => oldpass)
) ) );
IF SQL%ROWCOUNT = 0 THEN RAISE flipr_auth_failed; END IF;
END;
/
SHOW ERRORS;
-- Drop and die on error.
DECLARE
l_err_count INTEGER;
BEGIN
SELECT COUNT(*)
INTO l_err_count
FROM all_errors
WHERE owner = 'FLIPR'
AND name = 'CHANGE_PASS';
IF l_err_count > 0 THEN
EXECUTE IMMEDIATE 'DROP PROCEDURE flipr.CHANGE_PASS';
raise_application_error(-20001, 'Errors in FLIPR.CHANGE_PASS');
END IF;
END;
/
We again need the C<DECLARE> PL/SQL block to detect compilation warnings and
make the script die. Use C<DESCRIBE> in F<verify/change_pass.sql> again:
-- Verify flipr:change_pass on oracle
DESCRIBE flipr.change_pass;
And of course, its C<revert> script, F<revert/change_pass.sql>, should look
something like:
-- Revert flipr:change_pass from oracle
DROP PROCEDURE flipr.change_pass;
Try em out!
> sqitch deploy
Deploying changes to flipr_test
+ insert_user .. No errors.
ok
+ change_pass .. No errors.
ok
Looks good. The "No errors" notices come from the C<SHOW ERRORS> SQL*Plus
command. It's not very useful here, but very useful if there are compilation
errors. If it bothers you, you can drop the C<SHOW ERRORS> line and select the
error for display in the C<DECLARE> block, instead.
Now, do we have the functions? Of course we do, they were verified. Still,
have a look:
> echo "DESCRIBE flipr.insert_user;\nDESCRIBE flipr.change_pass;" \
| sqlplus -S scott/tiger@flipr_test
PROCEDURE flipr.insert_user
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
NICKNAME VARCHAR2 IN
PASSWORD VARCHAR2 IN
PROCEDURE flipr.change_pass
Argument Name Type In/Out Default?
------------------------------ ----------------------- ------ --------
NICK VARCHAR2 IN
OLDPASS VARCHAR2 IN
NEWPASS VARCHAR2 IN
And what's the status?
> sqitch status
# On database flipr_test
# Project: flipr
# Change: e1c9df6a95da835769eb560790588c16174f78df
# Name: change_pass
# Deployed: 2013-12-31 16:37:22 -0800
# By: Marge N. O’Vera <marge@example.com>
#
Nothing to deploy (up-to-date)
Looks good. Let's make sure revert works:
> sqitch revert -y --to @HEAD^^
Reverting changes to users from flipr_test
- change_pass .. ok
- insert_user .. ok
> echo "DESCRIBE flipr.insert_user;\nDESCRIBE flipr.change_pass;" \
| sqlplus -S dwheeler/dwheeler@flipr_test
ERROR:
ORA-04043: object flipr.insert_user does not exist
ERROR:
ORA-04043: object flipr.change_pass does not exist
Note the use of C<@HEAD^^> to specify that the revert be to two changes prior
the last deployed change. Looks good. Let's do the commit and re-deploy dance:
> git add .
> git commit -m 'Add `insert_user()` and `change_pass()`.'
[main 6b6797e] Add `insert_user()` and `change_pass()`.
7 files changed, 92 insertions(+)
create mode 100644 deploy/change_pass.sql
create mode 100644 deploy/insert_user.sql
create mode 100644 revert/change_pass.sql
create mode 100644 revert/insert_user.sql
create mode 100644 verify/change_pass.sql
create mode 100644 verify/insert_user.sql
> sqitch deploy
Deploying changes to flipr_test
+ insert_user .. No errors.
ok
+ change_pass .. No errors.
ok
> sqitch status
# On database flipr_test
# Project: flipr
# Change: e1c9df6a95da835769eb560790588c16174f78df
# Name: change_pass
# Deployed: 2013-12-31 16:38:46 -0800
# By: Marge N. O’Vera <marge@example.com>
#
Nothing to deploy (up-to-date)
> sqitch verify