1 package DBIx::DBSchema::Column;
6 use DBIx::DBSchema::_util qw(_load_driver _dbh _parse_opt);
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 $dbd = "DBIx::DBSchema::DBD::$driver";
258 %typemap = eval "\%${dbd}::typemap" if $driver;
259 my $type = defined( $typemap{uc($self->type)} )
260 ? $typemap{uc($self->type)}
264 # callback into the database-specific driver
267 my $hashref = $dbd->column_callback( $dbh, $self->table_name, $self );
269 $type = $hashref->{'effective_type'}
270 if $hashref->{'effective_type'};
272 my $null = $self->null;
274 #we seem to do this for mysql/Pg/SQLite, i think this should be the default
275 #add something to $hashref if drivers need to overrdide?
276 $null ||= "NOT NULL";
278 $null =~ s/^NULL$// unless $hashref->{'explicit_null'};
280 my $default = $hashref->{'effective_default'} || $self->quoted_default($dbh);
281 $default = "DEFAULT $default" if $default ne '';
283 my $local = $self->local;
284 $local = $hashref->{'effective_local'}
285 if $hashref->{'effective_local'};
293 $type. ( ( defined($self->length) && $self->length )
294 ? '('.$self->length.')'
299 ( defined($local) ? $local : ''),
304 =item quoted_default DATABASE_HANDLE
306 Returns this column's default value quoted for the database.
311 my($self, $dbh) = @_;
312 my $driver = $dbh ? _load_driver($dbh) : '';
314 return ${$self->default} if ref($self->default);
316 my $dbd = "DBIx::DBSchema::DBD::$driver";
318 return $dbh->quote($self->default)
319 if defined($self->default)
320 && $self->default ne ''
322 && $dbd->column_value_needs_quoting($self);
324 return $self->default;
328 =item sql_add_column [ DBH ]
330 Returns a list of SQL statements to add this column to an existing table. (To
331 create a new table, see L<DBIx::DBSchema::Table/sql_create_table> instead.)
333 The data source can be specified by passing an open DBI database handle, or by
334 passing the DBI data source name, username and password.
336 Although the username and password are optional, it is best to call this method
337 with a database handle or data source including a valid username and password -
338 a DBI connection will be opened and the quoting and type mapping will be more
341 If passed a DBI data source (or handle) such as `DBI:Pg:dbname=database', will
342 use PostgreSQL-specific syntax. Non-standard syntax for other engines (if
343 applicable) may also be supported in the future.
348 my($self, $dbh) = ( shift, _dbh(@_) );
350 die "$self: this column is not assigned to a table"
351 unless $self->table_name;
353 my $driver = $dbh ? _load_driver($dbh) : '';
356 my $table = $self->table_name;
358 my $dbd = "DBIx::DBSchema::DBD::$driver";
359 my $hashref = $dbd->add_column_callback( $dbh, $table, $self );
362 if ( $hashref->{'effective_type'} ) {
363 $real_type = $self->type;
364 $self->type($hashref->{'effective_type'});
367 my $real_null = undef;
368 if ( exists($hashref->{'effective_null'}) ) {
369 $real_null = $self->null;
370 $self->null($hashref->{'effective_null'});
373 push @sql, "ALTER TABLE $table ADD COLUMN ". $self->line($dbh);
375 push @sql, @{ $hashref->{'sql_after'} } if $hashref->{'sql_after'};
377 push @sql, "ALTER TABLE $table ADD PRIMARY KEY ( ".
378 $self->table_obj->primary_key. " )"
379 if $self->name eq $self->table_obj->primary_key;
381 $self->type($real_type) if $real_type;
382 $self->null($real_null) if defined $real_null;
388 =item sql_alter_column PROTOTYPE_COLUMN [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
390 Returns a list of SQL statements to alter this column so that it is identical
391 to the provided prototype column, also a DBIx::DBSchema::Column object.
393 Optionally, the data source can be specified by passing an open DBI database
394 handle, or by passing the DBI data source name, username and password.
396 If passed a DBI data source (or handle) such as `DBI:Pg:dbname=database', will
397 use PostgreSQL-specific syntax. Non-standard syntax for other engines (if
398 applicable) may also be supported in the future.
400 If not passed a data source (or handle), or if there is no driver for the
401 specified database, will attempt to use generic SQL syntax.
405 sub sql_alter_column {
406 my($self, $opt, $new, $dbh) = ( shift, _parse_opt(\@_), shift, _dbh(@_) );
408 my $table = $self->table_name;
409 die "$self: this column is not assigned to a table"
412 my $name = $self->name;
414 my $driver = $dbh ? _load_driver($dbh) : '';
418 my $dbd = "DBIx::DBSchema::DBD::$driver";
419 my $hashref = $dbd->alter_column_callback( $dbh, $table, $self, $new );
421 if ( $hashref->{'sql_alter'} ) {
423 push @sql, $hashref->{'sql_alter'};
428 # not yet implemented. how do we tell which old column it was?
431 if ( $hashref->{'sql_alter_type'} ) {
432 push @sql, $hashref->{'sql_alter_type'};
435 # change nullability...
437 if ( $hashref->{'sql_alter_null'} ) {
439 push @sql, $hashref->{'sql_alter_null'};
443 # change nullability from NOT NULL to NULL
444 if ( ! $self->null && $new->null ) {
446 push @sql, "ALTER TABLE $table ALTER COLUMN $name DROP NOT NULL";
450 # change nullability from NULL to NOT NULL...
451 # this one could be more complicated, need to set a DEFAULT value and update
453 if ( $self->null && ! $new->null ) {
455 push @sql, "ALTER TABLE $table ALTER COLUMN $name SET NOT NULL";
462 my $old_default = $self->quoted_default($dbh);
463 my $new_default = $new->quoted_default($dbh);
464 if ( $old_default ne $new_default
465 && ( uc($old_default) ne 'NOW()' || uc($new_default) ne 'NOW()' )
469 #warn "old default: $old_default / new default: $new_default\n";
471 my $alter = "ALTER TABLE $table ALTER COLUMN $name";
473 if ( $new_default ne '' ) {
474 #warn "changing from $old_default to $new_default\n";
475 push @sql, "$alter SET DEFAULT $new_default";
476 } elsif ( $old_default !~ /^nextval/i ) { #Pg-specific :(
477 push @sql, "$alter DROP DEFAULT";
479 push @sql, "UPDATE TABLE $table SET $name = NULL WHERE $name = ''"
480 if $opt->{'nullify_default'} && $old_default eq "''" && $new->null;
485 # change other stuff... (what next?)
493 =item sql_drop_column [ DBH ]
495 Returns a list of SQL statements to drop this column from an existing table.
497 The optional database handle or DBI data source/username/password is not yet
502 sub sql_drop_column {
503 my( $self, $dbh ) = ( shift, _dbh(@_) );
505 my $table = $self->table_name;
506 my $name = $self->name;
508 ("ALTER TABLE $table DROP COLUMN $name"); # XXX what about indexes???
515 Ivan Kohler <ivan-dbix-dbschema@420.am>
519 Copyright (c) 2000-2006 Ivan Kohler
520 Copyright (c) 2007-2010 Freeside Internet Services, Inc.
522 This program is free software; you can redistribute it and/or modify it under
523 the same terms as Perl itself.
527 The new() method should warn that
528 "Old-style $class creation without named parameters is deprecated!"
530 Better documentation is needed for sql_add_column
532 sql_alter_column() has database-specific foo that should be abstracted info
533 DBIx::DBSchema::DBD::Pg
535 nullify_default option should be documented
539 L<DBIx::DBSchema::Table>, L<DBIx::DBSchema>, L<DBIx::DBSchema::DBD>, L<DBI>