---
name: "DBIx::Class::DeploymentHandler::DeployMethod::SQL::Translator::ScriptHelpers"
section: "3pm"
platform: "linux"
package: "libdbix-class-deploymenthandler-perl"
version: "0.002234-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/DBIx::Class::DeploymentHandler::DeployMethod::SQL::Translator::ScriptHelpers"
---

# DBIx::Class::DeploymentHandler::DeployMethod::SQL::Translator::ScriptHelpers(3pm)

CodeRef Transforms for common use-cases in DBICDH Migrations

## NAME

DBIx::Class::DeploymentHandler::DeployMethod::SQL::Translator::ScriptHelpers - CodeRef Transforms for common use-cases in DBICDH Migrations

## SYNOPSIS

```
 use DBIx::Class::DeploymentHandler::DeployMethod::SQL::Translator::ScriptHelpers
   'schema_from_schema_loader';
   schema_from_schema_loader({ naming => 'v4' }, sub {
      my ($schema, $version_set) = @_;
      ...
   });
```

## DESCRIPTION

This package is a set of coderef transforms for common use-cases in migrations. The subroutines are simply helpers for creating coderefs that will work for "PERL SCRIPTS" in DBIx::Class::DeploymentHandler::DeployMethod::SQL::Translator, yet have some argument other than the current schema that you as a user might prefer.

## EXPORTED SUBROUTINES

### dbh($coderef)

```
 dbh(sub {
   my ($dbh, $version_set) = @_;
   ...
 });
```

For those times when you almost exclusively need access to "the bare metal". Simply gives you the correct database handle and the expected version set.

### schema\_from\_schema\_loader($sl\_opts, $coderef)

```
 schema_from_schema_loader({ naming => 'v4' }, sub {
   my ($schema, $version_set) = @_;
   ...
 });
```

Any time you write a perl migration script that uses a DBIx::Class::Schema you should probably use this.  Otherwise you'll run into problems if you remove a column from your schema yet still populate to it in an older population script.

Note that `$sl_opts` requires that you specify something for the `"naming"` option.

## CUSTOM SCRIPT HELPERS

If you find that in your scripts you need to always pass the same arguments to your script helpers, you may want to define a custom set of script helpers.  I am not sure that there is a better way than just using Perl and other modules that are already installed when you install DBIx::Class::DeploymentHandler.

The following is a pattern that will get you started; if anyone has ideas on how to make this even easier let me know.

```
 package MyApp::DBICDH::ScriptHelpers;
 use strict;
 use warnings;
 use DBIx::Class::DeploymentHandler::DeployMethod::SQL::Translator::ScriptHelpers
    dbh => { -as => '_old_dbh' },
    schema_from_schema_loader => { -as => '_old_sfsl' };
 use Sub::Exporter::Progressive -setup => {
    exports => [qw(dbh schema_from_schema_loader)],
 };
 sub dbh {
    my $coderef = shift;
    _old_dbh(sub {
       my ($dbh) = @_;
       $dbh->do(q(SET search_path TO 'myapp_db'));
       $coderef->(@_);
    });
 }
 sub schema_from_schema_loader {
    my ($config, $coderef) = @_;
    $config->{naming} ||= 'v7';
    _old_sfsl(sub {
       my ($schema) = @_;
       $schema->storage->dbh->do(q(SET search_path TO 'myapp_db'));
       $coderef->(@_);
    });
 }
```

The above will default the naming to `"v7"` when using `"schema_from_schema_loader"`.  And in both cases it will set the schema for PostgreSQL. Of course if you do that you will not be able to switch to MySQL or something else, so I recommended looking into my DBIx::Introspector to only do that for the database in question.

## AUTHOR

Arthur Axel "fREW" Schmidt \<frioux+cpan@gmail.com\>

## COPYRIGHT AND LICENSE

This software is copyright (c) 2024 by Arthur Axel "fREW" Schmidt.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.