DBIx::DBSchema::Column - Column objects


DBIx-DBSchema documentation  | view source Contained in the DBIx-DBSchema distribution.

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NAME

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DBIx::DBSchema::Column - Column objects

SYNOPSIS

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  use DBIx::DBSchema::Column;

  #named params with a hashref (preferred)
  $column = new DBIx::DBSchema::Column ( {
    'name'    => 'column_name',
    'type'    => 'varchar'
    'null'    => 'NOT NULL',
    'length'  => 64,
    'default' => '',
    'local'   => '',
  } );

  #list
  $column = new DBIx::DBSchema::Column ( $name, $sql_type, $nullability, $length, $default, $local );

  $name = $column->name;
  $column->name( 'name' );

  $sql_type = $column->type;
  $column->type( 'sql_type' );

  $null = $column->null;
  $column->null( 'NULL' );
  $column->null( 'NOT NULL' );
  $column->null( '' );

  $length = $column->length;
  $column->length( '10' );
  $column->length( '8,2' );

  $default = $column->default;
  $column->default( 'Roo' );

  $sql_line = $column->line;
  $sql_line = $column->line($datasrc);

  $sql_add_column = $column->sql_add_column;
  $sql_add_column = $column->sql_add_column($datasrc);

DESCRIPTION

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DBIx::DBSchema::Column objects represent columns in tables (see DBIx::DBSchema::Table).

METHODS

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new HASHREF
new [ name [ , type [ , null [ , length [ , default [ , local ] ] ] ] ] ]

Creates a new DBIx::DBSchema::Column object. Takes a hashref of named parameters, or a list. name is the name of the column. type is the SQL data type. null is the nullability of the column (intrepreted using Perl's rules for truth, with one exception: `NOT NULL' is false). length is the SQL length of the column. default is the default value of the column. local is reserved for database-specific information.

Note: If you pass a scalar reference as the default rather than a scalar value, it will be dereferenced and quoting will be forced off. This can be used to pass SQL functions such as now() or explicit empty strings as '' as defaults.

name [ NAME ]

Returns or sets the column name.

type [ TYPE ]

Returns or sets the column type.

null [ NULL ]

Returns or sets the column null flag (the empty string is equivalent to `NOT NULL')

length [ LENGTH ]

Returns or sets the column length.

default [ LOCAL ]

Returns or sets the default value.

local [ LOCAL ]

Returns or sets the database-specific field.

table_obj [ TABLE_OBJ ]

Returns or sets the table object (see DBIx::DBSchema::Table). Typically set internally when a column object is added to a table object.

table_name

Returns the table name, or the empty string if this column has not yet been assigned to a table.

line [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]

Returns an SQL column definition.

The data source can be specified by passing an open DBI database handle, or by passing the DBI data source name, username and password.

Although the username and password are optional, it is best to call this method with a database handle or data source including a valid username and password - a DBI connection will be opened and the quoting and type mapping will be more reliable.

If passed a DBI data source (or handle) such as `DBI:mysql:database' or `DBI:Pg:dbname=database', will use syntax specific to that database engine. Currently supported databases are MySQL and PostgreSQL. Non-standard syntax for other engines (if applicable) may also be supported in the future.

quoted_default DATABASE_HANDLE

Returns this column's default value quoted for the database.

sql_add_column [ DBH ]

Returns a list of SQL statements to add this column to an existing table. (To create a new table, see sql_create_table in DBIx::DBSchema::Table instead.)

The data source can be specified by passing an open DBI database handle, or by passing the DBI data source name, username and password.

Although the username and password are optional, it is best to call this method with a database handle or data source including a valid username and password - a DBI connection will be opened and the quoting and type mapping will be more reliable.

If passed a DBI data source (or handle) such as `DBI:Pg:dbname=database', will use PostgreSQL-specific syntax. Non-standard syntax for other engines (if applicable) may also be supported in the future.

sql_alter_column PROTOTYPE_COLUMN [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]

Returns a list of SQL statements to alter this column so that it is identical to the provided prototype column, also a DBIx::DBSchema::Column object.

Optionally, the data source can be specified by passing an open DBI database handle, or by passing the DBI data source name, username and password.

If passed a DBI data source (or handle) such as `DBI:Pg:dbname=database', will use PostgreSQL-specific syntax. Non-standard syntax for other engines (if applicable) may also be supported in the future.

If not passed a data source (or handle), or if there is no driver for the specified database, will attempt to use generic SQL syntax.

sql_drop_column [ DBH ]

Returns a list of SQL statements to drop this column from an existing table.

The optional database handle or DBI data source/username/password is not yet used.

AUTHOR

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Ivan Kohler <ivan-dbix-dbschema@420.am>

COPYRIGHT

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BUGS

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The new() method should warn that "Old-style $class creation without named parameters is deprecated!"

Better documentation is needed for sql_add_column

sql_alter_column() has database-specific foo that should be abstracted info DBIx::DBSchema::DBD::Pg

nullify_default option should be documented

SEE ALSO

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DBIx::DBSchema::Table, DBIx::DBSchema, DBIx::DBSchema::DBD, DBI


DBIx-DBSchema documentation  | view source Contained in the DBIx-DBSchema distribution.