https://github.com/grantstreetgroup/dbix-class-helper-resultset-mysqlhacks

Useful MySQL-specific operations for DBIx::Class
https://github.com/grantstreetgroup/dbix-class-helper-resultset-mysqlhacks

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Useful MySQL-specific operations for DBIx::Class

• Host: GitHub
• URL: https://github.com/grantstreetgroup/dbix-class-helper-resultset-mysqlhacks
• Owner: GrantStreetGroup
• License: other
• Created: 2021-02-09T03:12:43.000Z (almost 4 years ago)
• Default Branch: master
• Last Pushed: 2024-06-18T16:20:23.000Z (7 months ago)
• Last Synced: 2024-06-18T20:45:30.449Z (7 months ago)
• Language: Perl
• Size: 31.3 KB
• Stars: 0
• Watchers: 7
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE.txt

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README

        
# NAME

DBIx::Class::Helper::ResultSet::MySQLHacks - Useful MySQL-specific operations for DBIx::Class

# VERSION

version v1.0.0

# SYNOPSIS

    # Your base resultset

    package MySchema::ResultSet;

    use strict;

    use warnings;

    use parent 'DBIx::Class::ResultSet';

    __PACKAGE__->load_components('Helper::ResultSet::MySQLHacks');

    # In other resultset classes

    package MySchema::ResultSet::Bar;

    use strict;

    use warnings;

    use parent 'MySchema::ResultSet';

    # In code using the resultset

    $rs->multi_table_delete(qw< rel1 rel2 >);

    $rs->multi_table_update(\%values);

# DESCRIPTION

This MySQL-specific ResultSet helper contains a series of hacks for various SQL

operations that only work for MySQL.  These hacks are exactly that, so it's possible that

the SQL manipulation isn't as clean as it should be.

# METHODS

## multi\_table\_delete

    my $underlying_storage_rv = $rs->multi_table_delete;  # deletes rows from the current table

    my $underlying_storage_rv = $rs->multi_table_delete(qw< rel1 rel2 >);

Runs a delete using the multiple table syntax, which supports join operations.  This is

useful in cases with a joined ResultSet that require rows to be deleted, and using

["delete\_all" in DBIx::Class::ResultSet](https://metacpan.org/pod/DBIx%3A%3AClass%3A%3AResultSet#delete_all) would be too slow.

Without arguments, it will delete rows from the current table, ie: ["current\_source\_alias" in DBIx::Class::ResultSet](https://metacpan.org/pod/DBIx%3A%3AClass%3A%3AResultSet#current_source_alias).

Otherwise, it can take a list of **relationships** to delete from.  These must be existing

relationship aliases tied to the joins, not table names.

This method works by taking a count ResultSet, removing the `SELECT COUNT(*)`

portion, and splicing in the `DELETE @aliases` part.

The return value is a pass through of what the underlying storage backend returned, and

may vary.  See ["execute" in DBI](https://metacpan.org/pod/DBI#execute) for the most common case.

**NOTE:** This method will not delete from views, per MySQL limitations.

## multi\_table\_update

    my $underlying_storage_rv = $rs->multi_table_update(\%values);

Runs a update using the multiple table syntax, which supports join operations.  This is

useful in cases with a joined ResultSet that require rows to be updated, and using

["update\_all" in DBIx::Class::ResultSet](https://metacpan.org/pod/DBIx%3A%3AClass%3A%3AResultSet#update_all) would be too slow.

A values hashref is required.  It's highly recommended that the keys are named as

`alias.column` pairs, since multiple tables are involved.

This method works by acquiring the `FROM`, `SET`, and `WHERE` clauses separately and

merging them back into a proper multi-table `UPDATE` query.

The return value is a pass through of what the underlying storage backend returned, and

may vary.  See ["execute" in DBI](https://metacpan.org/pod/DBI#execute) for the most common case.

## dbh\_execute

    my $rv                = $rs->dbh_execute($sql, $bind);

    my ($rv, $sth, @bind) = $rs->dbh_execute($sql, $bind);

Sends any SQL statement to the `$dbh` via ["dbh\_do" in DBIx::Class::Storage::DBI](https://metacpan.org/pod/DBIx%3A%3AClass%3A%3AStorage%3A%3ADBI#dbh_do) while

running the usual query loggers and re-connection protections that come with DBIC.

This runs code similar to [DBIx::Class::Storage::DBI](https://metacpan.org/pod/DBIx%3A%3AClass%3A%3AStorage%3A%3ADBI)'s `_execute` method, except that

it takes SQL and binds as input.  Like `_dbh_execute` and `_execute`, it returns

different outputs, depending on the context.

# AUTHOR

Grant Street Group 

# COPYRIGHT AND LICENSE

This software is Copyright (c) 2021 by Grant Street Group.

This is free software, licensed under:

    The Artistic License 2.0 (GPL Compatible)