NAME

Tangram::Scalar - map scalar fields

SYNOPSIS

   use Tangram;

   Tangram::Schema->new(
      classes => { NaturalPerson => { fields => {
         string => [ qw( name firstName gender ) ],
         int => [ qw( age ) ],
         real => [ qw( height weight ) ],

   $schema = Tangram::Schema->new(
      classes => { NaturalPerson => { fields => {
         string =>
         {
            name    => { sql => 'VARCHAR(100)' },

            1stname => {
               col => 'firstName',
               sql => 'VARCHAR(100) NULL' },

            gender    => undef()
         },

DESCRIPTION

Classes Tangram::String, ::Int and ::Real and ::Ref are responsible for mapping the various subtypes of scalars. The first three mappings are documented here since they differ very little. See Tangram::Ref for information on mapping references.

Tangram::String uses DBI's quote() method to quote strings if that method is available, thus making it possible to store binary objects or multiline text in databases that support it (thanks to Marian Kelc <marian.kelc@ruhr-uni-bochum.de> for suggesting this improvement).

The three predefined typetags string, int and real are for the corresponding Perl scalar subtypes.

Each scalar field is stored in a single column of the table associated to the class.

The persistent fields may be specified either as a hash or as an array of field names.

In the hash form, each entry consists in a field name and an associated option hash. The option hash may contain the following fields:

• col

• sql

• automatic

col sets the name of the column used to store the field's value. This field is optional, it defaults to the persistent field name. Override if the field name is not an acceptable SQL column name.

sql sets the SQL type of the column. Used by Schema::deploy() when initializing a database. Defaults to 'VARCHAR(255) NULL' for strings, 'INT NULL' for ints and 'REAL NULL' for reals.

automatic, if set to true, tells Tangram not to save the field to storage. This is useful for auto-increment or timestamp columns.

The persistent fields may also be specified as an array of strings, in which case the defaults are used.