1 package DBIx::DBSchema::Column;
6 use DBIx::DBSchema::_util qw(_load_driver _dbh);
12 DBIx::DBSchema::Column - Column objects
16 use DBIx::DBSchema::Column;
18 #named params with a hashref (preferred)
19 $column = new DBIx::DBSchema::Column ( {
20 'name' => 'column_name',
29 $column = new DBIx::DBSchema::Column ( $name, $sql_type, $nullability, $length, $default, $local );
31 $name = $column->name;
32 $column->name( 'name' );
34 $sql_type = $column->type;
35 $column->type( 'sql_type' );
37 $null = $column->null;
38 $column->null( 'NULL' );
39 $column->null( 'NOT NULL' );
42 $length = $column->length;
43 $column->length( '10' );
44 $column->length( '8,2' );
46 $default = $column->default;
47 $column->default( 'Roo' );
49 $sql_line = $column->line;
50 $sql_line = $column->line($datasrc);
52 $sql_add_column = $column->sql_add_column;
53 $sql_add_column = $column->sql_add_column($datasrc);
57 DBIx::DBSchema::Column objects represent columns in tables (see
58 L<DBIx::DBSchema::Table>).
66 =item new [ name [ , type [ , null [ , length [ , default [ , local ] ] ] ] ] ]
68 Creates a new DBIx::DBSchema::Column object. Takes a hashref of named
69 parameters, or a list. B<name> is the name of the column. B<type> is the SQL
70 data type. B<null> is the nullability of the column (intrepreted using Perl's
71 rules for truth, with one exception: `NOT NULL' is false). B<length> is the
72 SQL length of the column. B<default> is the default value of the column.
73 B<local> is reserved for database-specific information.
75 Note: If you pass a scalar reference as the B<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 C<$now()> or explicit empty strings as C<''> as
82 my $class = ref($proto) || $proto;
88 #carp "Old-style $class creation without named parameters is deprecated!";
89 #croak "FATAL: old-style $class creation no longer supported;".
90 # " use named parameters";
92 $self = { map { $_ => shift } qw(name type null length default local) };
95 #croak "Illegal name: ". $self->{'name'}
96 # if grep $self->{'name'} eq $_, @reserved_words;
98 $self->{'null'} =~ s/^NOT NULL$//i;
99 $self->{'null'} = 'NULL' if $self->{'null'};
101 bless ($self, $class);
107 Returns or sets the column name.
113 if ( defined($value) ) {
114 #croak "Illegal name: $name" if grep $name eq $_, @reserved_words;
115 $self->{'name'} = $value;
123 Returns or sets the column type.
129 if ( defined($value) ) {
130 $self->{'type'} = $value;
138 Returns or sets the column null flag (the empty string is equivalent to
145 if ( defined($value) ) {
146 $value =~ s/^NOT NULL$//i;
147 $value = 'NULL' if $value;
148 $self->{'null'} = $value;
154 =item length [ LENGTH ]
156 Returns or sets the column length.
162 if ( defined($value) ) {
163 $self->{'length'} = $value;
169 =item default [ LOCAL ]
171 Returns or sets the default value.
177 if ( defined($value) ) {
178 $self->{'default'} = $value;
185 =item local [ LOCAL ]
187 Returns or sets the database-specific field.
193 if ( defined($value) ) {
194 $self->{'local'} = $value;
200 =item table_obj [ TABLE_OBJ ]
202 Returns or sets the table object (see L<DBIx::DBSchema::Table>). Typically
203 set internally when a column object is added to a table object.
209 if ( defined($value) ) {
210 $self->{'table_obj'} = $value;
212 $self->{'table_obj'};
218 Returns the table name, or the empty string if this column has not yet been
225 $self->{'table_obj'} ? $self->{'table_obj'}->name : '';
228 =item line [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
230 Returns an SQL column definition.
232 The data source can be specified by passing an open DBI database handle, or by
233 passing the DBI data source name, username and password.
235 Although the username and password are optional, it is best to call this method
236 with a database handle or data source including a valid username and password -
237 a DBI connection will be opened and the quoting and type mapping will be more
240 If passed a DBI data source (or handle) such as `DBI:mysql:database' or
241 `DBI:Pg:dbname=database', will use syntax specific to that database engine.
242 Currently supported databases are MySQL and PostgreSQL. Non-standard syntax
243 for other engines (if applicable) may also be supported in the future.
248 my($self, $dbh) = ( shift, _dbh(@_) );
250 my $driver = $dbh ? _load_driver($dbh) : '';
251 my $driver_class = "DBIx::DBSchema::DBD::${driver}";
258 %typemap = eval "\%${driver_class}::typemap" if $driver;
259 my $type = defined( $typemap{uc($self->type)} )
260 ? $typemap{uc($self->type)}
264 # set default for the callback...
268 my $orig_default = $self->default;
269 if ( $driver_class->can("_column_value_needs_quoting") ) {
270 if ( $driver_class->_column_value_needs_quoting($self)
271 && !ref($self->default)
274 $default = $dbh->quote($self->default);
276 $default = ref($self->default) ? ${$self->default} : $self->default;
278 } elsif ( defined($self->default) && !ref($self->default) && $self->default ne ''
280 # false laziness: nicked from FS::Record::_quote
281 && ( $self->default !~ /^\-?\d+(\.\d+)?$/
282 || $type =~ /(char|binary|blob|text)$/i
285 $default = $dbh->quote($self->default);
287 $default = ref($self->default) ? ${$self->default} : $self->default;
289 $self->default($default);
292 # callback into the database-specific driver
295 my $dbd = "DBIx::DBSchema::DBD::$driver";
296 my $hashref = $dbd->column_callback( $dbh, $self->table_name, $self );
298 $self->default($orig_default);
300 $type = $hashref->{'effective_type'}
301 if $hashref->{'effective_type'};
303 my $null = $self->null;
305 #we seem to do this for mysql/Pg/SQLite, i think this should be the default
306 #add something to $hashref if drivers need to overrdide?
307 $null ||= "NOT NULL";
309 $null =~ s/^NULL$// unless $hashref->{'explicit_null'};
311 $default = $hashref->{'effective_default'}
312 if $hashref->{'effective_default'};
314 my $local = $self->local;
315 $local = $hashref->{'effective_local'}
316 if $hashref->{'effective_local'};
324 $type. ( ( defined($self->length) && $self->length )
325 ? '('.$self->length.')'
329 ( ( defined($default) && $default ne '' )
330 ? 'DEFAULT '. $default
333 ( defined($local) ? $local : ''),
338 =item sql_add_column [ DBH ]
340 Returns a list of SQL statements to add this column to an existing table. (To
341 create a new table, see L<DBIx::DBSchema::Table/sql_create_table> instead.)
343 The data source can be specified by passing an open DBI database handle, or by
344 passing the DBI data source name, username and password.
346 Although the username and password are optional, it is best to call this method
347 with a database handle or data source including a valid username and password -
348 a DBI connection will be opened and the quoting and type mapping will be more
351 If passed a DBI data source (or handle) such as `DBI:Pg:dbname=database', will
352 use PostgreSQL-specific syntax. Non-standard syntax for other engines (if
353 applicable) may also be supported in the future.
358 my($self, $dbh) = ( shift, _dbh(@_) );
360 die "$self: this column is not assigned to a table"
361 unless $self->table_name;
363 my $driver = $dbh ? _load_driver($dbh) : '';
366 my $table = $self->table_name;
368 my $dbd = "DBIx::DBSchema::DBD::$driver";
369 my $hashref = $dbd->add_column_callback( $dbh, $table, $self );
372 if ( $hashref->{'effective_type'} ) {
373 $real_type = $self->type;
374 $self->type($hashref->{'effective_type'});
377 my $real_null = undef;
378 if ( exists($hashref->{'effective_null'}) ) {
379 $real_null = $self->null;
380 $self->null($hashref->{'effective_null'});
383 push @sql, "ALTER TABLE $table ADD COLUMN ". $self->line($dbh);
385 push @sql, @{ $hashref->{'sql_after'} } if $hashref->{'sql_after'};
387 push @sql, "ALTER TABLE $table ADD PRIMARY KEY ( ".
388 $self->table_obj->primary_key. " )"
389 if $self->name eq $self->table_obj->primary_key;
391 $self->type($real_type) if $real_type;
392 $self->null($real_null) if defined $real_null;
398 =item sql_alter_column PROTOTYPE_COLUMN [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
400 Returns a list of SQL statements to alter this column so that it is identical
401 to the provided prototype column, also a DBIx::DBSchema::Column object.
403 #Optionally, the data source can be specified by passing an open DBI database
404 #handle, or by passing the DBI data source name, username and password.
406 #If passed a DBI data source (or handle) such as `DBI:Pg:dbname=database', will
407 #use PostgreSQL-specific syntax. Non-standard syntax for other engines (if
408 #applicable) may also be supported in the future.
410 #If not passed a data source (or handle), or if there is no driver for the
411 #specified database, will attempt to use generic SQL syntax.
414 Or should, someday. Right now it knows how to change NOT NULL into NULL and
419 sub sql_alter_column {
420 my( $self, $new, $dbh ) = ( shift, shift, _dbh(@_) );
422 my $table = $self->table_name;
423 die "$self: this column is not assigned to a table"
426 my $name = $self->name;
428 my $driver = $dbh ? _load_driver($dbh) : '';
432 my $dbd = "DBIx::DBSchema::DBD::$driver";
433 my $hashref = $dbd->alter_column_callback( $dbh, $table, $self, $new );
435 if ( $hashref->{'sql_alter'} ) {
437 push @sql, $hashref->{'sql_alter'};
442 # not yet implemented. how do we tell which old column it was?
445 if ( $hashref->{'sql_alter_type'} ) {
446 push @sql, $hashref->{'sql_alter_type'};
449 # change nullability...
451 if ( $hashref->{'sql_alter_null'} ) {
453 push @sql, $hashref->{'sql_alter_null'};
457 # change nullability from NOT NULL to NULL
458 if ( ! $self->null && $new->null ) {
460 push @sql, "ALTER TABLE $table ALTER COLUMN $name DROP NOT NULL";
464 # change nullability from NULL to NOT NULL...
465 # this one could be more complicated, need to set a DEFAULT value and update
467 if ( $self->null && ! $new->null ) {
469 push @sql, "ALTER TABLE $table ALTER COLUMN $name SET NOT NULL";
477 # change other stuff...
484 =item sql_drop_column [ DBH ]
486 Returns a list of SQL statements to drop this column from an existing table.
488 The optional database handle or DBI data source/username/password is not yet
493 sub sql_drop_column {
494 my( $self, $dbh ) = ( shift, _dbh(@_) );
496 my $table = $self->table_name;
497 my $name = $self->name;
499 ("ALTER TABLE $table DROP COLUMN $name"); # XXX what about indexes???
506 Ivan Kohler <ivan-dbix-dbschema@420.am>
510 Copyright (c) 2000-2006 Ivan Kohler
511 Copyright (c) 2007 Freeside Internet Services, Inc.
513 This program is free software; you can redistribute it and/or modify it under
514 the same terms as Perl itself.
518 The new() method should warn that
519 "Old-style $class creation without named parameters is deprecated!"
521 Better documentation is needed for sql_add_column
523 line() and sql_add_column() hav database-specific foo that should be abstracted
524 into the DBIx::DBSchema:DBD:: modules.
528 L<DBIx::DBSchema::Table>, L<DBIx::DBSchema>, L<DBIx::DBSchema::DBD>, L<DBI>