[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Manual / Glossary.pod

=head1 NAME

DBIx::Class::Manual::Glossary - Clarification of terms used.

=head1 INTRODUCTION

This document lists various terms used in DBIx::Class and attempts to
explain them.

=head1 TERMS

=head2 Inflation

The act of turning database row data into objects in
language-space. DBIx::Class further allows you to inflate your data
into perl objects which more usefully represent their contents. For
example: L<DBIx::Class::InflateColumn::DateTime> for datetime or
timestamp column data.

=head2 Join

This is an SQL keyword that gets mentioned a lot. It is used to fetch
data from more than one table at once, by C<join>ing the tables on
fields where they have common data.

=head2 Normalisation

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 L<DBIx::Class::Manual::FAQ|the FAQ>.

=head2 ORM

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.

=head2 Relationship

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.

=head2 Relationship bridge

A relationship bridge, such as C<many_to_many> defines an accessor to
retrieve row contents across multiple relationships.

=head2 ResultSet

This is an object representing a set of 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: L<DBIx::Class::ResultSet/METHODS>

=head2 ResultSource

ResultSource objects represent the source of your data, they are also known as
a table objects. 

See also: L<DBIx::Class::ResultSource/METHODS>

=head2 Record

See Row.

=head2 Row

Row objects contain your actual data. They are returned from ResultSet objects.

=head2 Object

See Row.

=head2 Schema

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 (ResultSource) definitions.
Commit	Line	Data
24105556	1	=head1 NAME
24105556	2
880a1a0c	3	DBIx::Class::Manual::Glossary - Clarification of terms used.
24105556	4
	5	=head1 INTRODUCTION
	6
9e7b9292	7	This document lists various terms used in DBIx::Class and attempts to
9e7b9292	8	explain them.
24105556	9
	10	=head1 TERMS
	11
9e7b9292	12	=head2 Inflation
	13
	14	The act of turning database row data into objects in
	15	language-space. DBIx::Class further allows you to inflate your data
	16	into perl objects which more usefully represent their contents. For
	17	example: L<DBIx::Class::InflateColumn::DateTime> for datetime or
	18	timestamp column data.
	19
	20	=head2 Join
	21
	22	This is an SQL keyword that gets mentioned a lot. It is used to fetch
	23	data from more than one table at once, by C<join>ing the tables on
	24	fields where they have common data.
	25
	26	=head2 Normalisation
	27
	28	A normalised database is a sane database. Each table contains only
	29	data belonging to one concept, related tables refer to the key field
	30	or fields of each other. Some links to webpages about normalisation
	31	can be found in L<DBIx::Class::Manual::FAQ\|the FAQ>.
	32
24105556	33	=head2 ORM
24105556	34
9e7b9292	35	Object-relational mapping, or Object-relationship modelling. Either
	36	way it's a method of mapping the contents of database tables (rows),
	37	to objects in programming-language-space. DBIx::Class is an ORM.
	38
7cf4ae7a	39	=head2 Relationship
	40
	41	In DBIx::Class a relationship defines the connection between exactly
	42	two tables. The relationship condition lists the columns in each table
	43	that contain the same values. It is used to output an SQL JOIN
	44	condition between the tables.
	45
	46	=head2 Relationship bridge
	47
	48	A relationship bridge, such as C<many_to_many> defines an accessor to
	49	retrieve row contents across multiple relationships.
	50
24105556	51	=head2 ResultSet
	52
	53	This is an object representing a set of data. It can either be an
	54	entire table, or the results of a query. The actual data is not held
	55	in the ResultSet, it is only a description of how to fetch the data.
	56
	57	See also: L<DBIx::Class::ResultSet/METHODS>
	58
	59	=head2 ResultSource
	60
	61	ResultSource objects represent the source of your data, they are also known as
	62	a table objects.
	63
	64	See also: L<DBIx::Class::ResultSource/METHODS>
	65
	66	=head2 Record
	67
	68	See Row.
	69
	70	=head2 Row
	71
	72	Row objects contain your actual data. They are returned from ResultSet objects.
	73
	74	=head2 Object
	75
	76	See Row.
	77
	78	=head2 Schema
	79
	80	A Schema object represents your entire table collection, plus the
	81	connection to the database. You can create one or more schema objects,
	82	connected to various databases, with various users, using the same set
	83	of table (ResultSource) definitions.