DBIx::Class::Manual::Glossary - Clarification of terms used.
This document lists various terms used in DBIx::Class and attempts to explain
Refers to a single physical schema within an RDBMS. Synonymous with the terms
'database', for MySQL; and 'schema', for most other RDBMS(s).
In other words, it's the 'xyz' _thing_ you're connecting to when using any of
the following DSN(s):
The act of turning database row data into objects in language-space. DBIx::Class
result classes can be set up to inflate your data into perl objects which more
usefully represent their contents. For example:
DBIx::Class::InflateColumn::DateTime for datetime or timestamp column data.
See also DBIx::Class::InflateColumn.
The opposite of "Inflation". Existing perl objects that represent
column values can be passed to DBIx::Class methods to store into the database.
For example a DateTime object can be automatically deflated into a datetime
string for insertion.
See DBIx::Class::InflateColumn and other modules in that namespace.
Object-relational mapping, or Object-relationship modelling. Either way it's a
method of mapping the contents of database tables (rows), to objects in
programming-language-space. DBIx::Class is an ORM.
In DBIx::Class a relationship defines the connection between exactly two tables.
The relationship condition lists the columns in each table that contain the
same values. It is used to output an SQL JOIN condition between the tables.
A relationship bridge, such as "many_to_many" defines an accessor to
retrieve row contents across multiple relationships.
The difference between a bridge and a relationship is, that the bridge cannot be
used to "join" tables in a "search", instead its component
relationships must be used.
A Schema object represents your entire table collection, plus the connection to
the database. You can create one or more schema objects, connected to various
databases, with various users, using the same set of table "Result
At least one DBIx::Class::Schema class is needed per database.
A Result class defines both a source of data (usually one per table), and the
methods that will be available in the "Result" objects created using
One Result class is needed per data source (table, view, query) used in your
application, they should inherit from DBIx::Class::Core.
See also: DBIx::Class::Manual::ResultClass
ResultSource objects represent the source of your data, these are sometimes
(incorrectly) called table objects.
ResultSources do not need to be directly created, a ResultSource instance is
created for each "Result Class" in your "Schema", by the
proxied methods "table" and "add_columns".
See also: "METHODS" in DBIx::Class::ResultSource
This is an object representing a set of conditions to filter data. It can either
be an entire table, or the results of a query. The actual data is not held in
the ResultSet, it is only a description of how to fetch the data.
See also: "METHODS" in DBIx::Class::ResultSet
Result objects contain your actual data. They are returned from ResultSet
objects. These are sometimes (incorrectly) called row objects, including older
versions of the DBIC documentation.
See also: DBIx::Class::Manual::ResultClass
Similar to a join, except the related result objects are fetched and cached for
future use, instead of used directly from the ResultSet. This allows you to
jump to different relationships within a Result without worrying about
generating a ton of extra SELECT statements.
Create, Read, Update, Delete. A general concept of something that can do all
four operations (INSERT, SELECT, UPDATE, DELETE), usually at a row-level.
This is an SQL keyword, it is used to link multiple tables in one SQL statement.
This enables us to fetch data from more than one table at once, or filter data
based on content in another table, without having to issue multiple SQL
A normalised database is a sane database. Each table contains only data
belonging to one concept, related tables refer to the key field or fields of
each other. Some links to webpages about normalisation can be found in the
In SQL, related data actually refers to data that are normalised into the same
table. (Yes. DBIC does mis-use this term.)
Check the list of additional DBIC resources.
This module is free software copyright by the DBIx::Class (DBIC) authors. You
can redistribute it and/or modify it under the same terms as the DBIx::Class