package DBIx::DBSchema::Column;
use strict;
-use vars qw(@ISA);
-#use Carp;
-#use Exporter;
+use vars qw($VERSION);
+use Carp;
+use DBIx::DBSchema::_util qw(_load_driver _dbh _parse_opt);
-#@ISA = qw(Exporter);
-@ISA = qw();
+$VERSION = '0.14';
=head1 NAME
use DBIx::DBSchema::Column;
- $column = new DBIx::DBSchema::Column ( $name, $sql_type, '' );
- $column = new DBIx::DBSchema::Column ( $name, $sql_type, 'NULL' );
- $column = new DBIx::DBSchema::Column ( $name, $sql_type, '', $length );
- $column = new DBIx::DBSchema::Column ( $name, $sql_type, 'NULL', $length );
- $column = new DBIx::DBSchema::Column ( $name, $sql_type, 'NULL', $length, $default, $local );
+ #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->sql_type( 'sql_type' );
+ $column->type( 'sql_type' );
$null = $column->null;
$column->null( 'NULL' );
$sql_line = $column->line;
$sql_line = $column->line($datasrc);
+ $sql_add_column = $column->sql_add_column;
+ $sql_add_column = $column->sql_add_column($datasrc);
+
=head1 DESCRIPTION
DBIx::DBSchema::Column objects represent columns in tables (see
=over 4
-=item new [ NAME [ , SQL_TYPE [ , NULL [ , LENGTH [ , DEFAULT [ , LOCAL ] ] ] ] ] ]
+=item new HASHREF
+
+=item new [ name [ , type [ , null [ , length [ , default [ , local ] ] ] ] ] ]
+
+Creates a new DBIx::DBSchema::Column object. Takes a hashref of named
+parameters, or a list. B<name> is the name of the column. B<type> is the SQL
+data type. B<null> is the nullability of the column (intrepreted using Perl's
+rules for truth, with one exception: `NOT NULL' is false). B<length> is the
+SQL length of the column. B<default> is the default value of the column.
+B<local> is reserved for database-specific information.
-Creates a new DBIx::DBSchema::Column object. NAME is the name of the column.
-SQL_TYPE is the SQL data type. NULL is the nullability of the column (the
-empty string is equivalent to `NOT NULL'). 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 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
+defaults.
=cut
sub new {
- my($proto,$name,$type,$null,$length,$default,$local)=@_;
+ my $proto = shift;
+ my $class = ref($proto) || $proto;
- #croak "Illegal name: $name" if grep $name eq $_, @reserved_words;
+ my $self;
+ if ( ref($_[0]) ) {
+ $self = shift;
+ } else {
+ #carp "Old-style $class creation without named parameters is deprecated!";
+ #croak "FATAL: old-style $class creation no longer supported;".
+ # " use named parameters";
+
+ $self = { map { $_ => shift } qw(name type null length default local) };
+ }
- $null =~ s/^NOT NULL$//i;
- $null = 'NULL' if $null;
+ #croak "Illegal name: ". $self->{'name'}
+ # if grep $self->{'name'} eq $_, @reserved_words;
- my $class = ref($proto) || $proto;
- my $self = {
- 'name' => $name,
- 'type' => $type,
- 'null' => $null,
- 'length' => $length,
- 'default' => $default,
- 'local' => $local,
- };
+ $self->{'null'} =~ s/^NOT NULL$//i;
+ $self->{'null'} = 'NULL' if $self->{'null'};
bless ($self, $class);
}
}
-=item line [ $datasrc ]
+=item table_obj [ TABLE_OBJ ]
+
+Returns or sets the table object (see L<DBIx::DBSchema::Table>). Typically
+set internally when a column object is added to a table object.
+
+=cut
+
+sub table_obj {
+ my($self,$value)=@_;
+ if ( defined($value) ) {
+ $self->{'table_obj'} = $value;
+ } else {
+ $self->{'table_obj'};
+ }
+}
+
+=item table_name
+
+Returns the table name, or the empty string if this column has not yet been
+assigned to a table.
+
+=cut
+
+sub table_name {
+ my $self = shift;
+ $self->{'table_obj'} ? $self->{'table_obj'}->name : '';
+}
+
+=item line [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
Returns an SQL column definition.
-If passed a DBI data source such as `DBI:mysql:database' or
+The data source can be specified by passing an open DBI database handle, or by
+passing the DBI data source name, username and password.
+
+Although the username and password are optional, it is best to call this method
+with a database handle or data source including a valid username and password -
+a DBI connection will be opened and the quoting and type mapping will be more
+reliable.
+
+If passed a DBI data source (or handle) such as `DBI:mysql:database' or
`DBI:Pg:dbname=database', will use syntax specific to that database engine.
Currently supported databases are MySQL and PostgreSQL. Non-standard syntax
for other engines (if applicable) may also be supported in the future.
=cut
sub line {
- my($self,$datasrc)=@_;
-
- my $driver = DBIx::DBSchema::_load_driver($datasrc);
- my %typemap = eval "\%DBIx::DBSchema::DBD::${driver}::typemap";
+ my($self, $dbh) = ( shift, _dbh(@_) );
+
+ my $driver = $dbh ? _load_driver($dbh) : '';
+ my $dbd = "DBIx::DBSchema::DBD::$driver";
+
+ ##
+ # type mapping
+ ##
+
+ my %typemap;
+ %typemap = eval "\%${dbd}::typemap" if $driver;
my $type = defined( $typemap{uc($self->type)} )
? $typemap{uc($self->type)}
: $self->type;
- my($null)=$self->null;
+ ##
+ # callback into the database-specific driver
+ ##
- if ( $datasrc =~ /^dbi:mysql:/i ) { #yucky mysql hack
- $null ||= "NOT NULL"
- }
- if ( $datasrc =~ /^dbi:pg/i ) { #yucky Pg hack
- $null ||= "NOT NULL";
- $null =~ s/^NULL$//;
- }
+ my $hashref = $dbd->column_callback( $dbh, $self->table_name, $self );
+
+ $type = $hashref->{'effective_type'}
+ if $hashref->{'effective_type'};
+
+ my $null = $self->null;
+
+ #we seem to do this for mysql/Pg/SQLite, i think this should be the default
+ #add something to $hashref if drivers need to overrdide?
+ $null ||= "NOT NULL";
+
+ $null =~ s/^NULL$// unless $hashref->{'explicit_null'};
+
+ my $default = $hashref->{'effective_default'} || $self->quoted_default($dbh);
+ $default = "DEFAULT $default" if $default ne '';
+
+ my $local = $self->local;
+ $local = $hashref->{'effective_local'}
+ if $hashref->{'effective_local'};
+
+ ##
+ # return column line
+ ##
join(' ',
$self->name,
- $type. ( $self->length ? '('.$self->length.')' : '' ),
+ $type. ( ( defined($self->length) && $self->length )
+ ? '('.$self->length.')'
+ : ''
+ ),
$null,
- ( ( defined($self->default) && $self->default ne '' )
- ? 'DEFAULT '. $self->default
- : ''
- ),
- ( ( $datasrc =~ /^dbi:mysql:/i )
- ? $self->local
- : ''
- ),
+ $default,
+ ( defined($local) ? $local : ''),
);
}
+=item quoted_default DATABASE_HANDLE
+
+Returns this column's default value quoted for the database.
+
+=cut
+
+sub quoted_default {
+ my($self, $dbh) = @_;
+ my $driver = $dbh ? _load_driver($dbh) : '';
+
+ return ${$self->default} if ref($self->default);
+
+ my $dbd = "DBIx::DBSchema::DBD::$driver";
+
+ return $dbh->quote($self->default)
+ if defined($self->default)
+ && $self->default ne ''
+ && ref($dbh)
+ && $dbd->column_value_needs_quoting($self);
+
+ return $self->default;
+
+}
+
+=item sql_add_column [ DBH ]
+
+Returns a list of SQL statements to add this column to an existing table. (To
+create a new table, see L<DBIx::DBSchema::Table/sql_create_table> instead.)
+
+The data source can be specified by passing an open DBI database handle, or by
+passing the DBI data source name, username and password.
+
+Although the username and password are optional, it is best to call this method
+with a database handle or data source including a valid username and password -
+a DBI connection will be opened and the quoting and type mapping will be more
+reliable.
+
+If passed a DBI data source (or handle) such as `DBI:Pg:dbname=database', will
+use PostgreSQL-specific syntax. Non-standard syntax for other engines (if
+applicable) may also be supported in the future.
+
+=cut
+
+sub sql_add_column {
+ my($self, $dbh) = ( shift, _dbh(@_) );
+
+ die "$self: this column is not assigned to a table"
+ unless $self->table_name;
+
+ my $driver = $dbh ? _load_driver($dbh) : '';
+
+ my @sql = ();
+ my $table = $self->table_name;
+
+ my $dbd = "DBIx::DBSchema::DBD::$driver";
+ my $hashref = $dbd->add_column_callback( $dbh, $table, $self );
+
+ my $real_type = '';
+ if ( $hashref->{'effective_type'} ) {
+ $real_type = $self->type;
+ $self->type($hashref->{'effective_type'});
+ }
+
+ my $real_null = undef;
+ if ( exists($hashref->{'effective_null'}) ) {
+ $real_null = $self->null;
+ $self->null($hashref->{'effective_null'});
+ }
+
+ push @sql, "ALTER TABLE $table ADD COLUMN ". $self->line($dbh);
+
+ push @sql, @{ $hashref->{'sql_after'} } if $hashref->{'sql_after'};
+
+ push @sql, "ALTER TABLE $table ADD PRIMARY KEY ( ".
+ $self->table_obj->primary_key. " )"
+ if $self->name eq $self->table_obj->primary_key;
+
+ $self->type($real_type) if $real_type;
+ $self->null($real_null) if defined $real_null;
+
+ @sql;
+
+}
+
+=item sql_alter_column PROTOTYPE_COLUMN [ DATABASE_HANDLE | DATA_SOURCE [ USERNAME PASSWORD [ ATTR ] ] ]
+
+Returns a list of SQL statements to alter this column so that it is identical
+to the provided prototype column, also a DBIx::DBSchema::Column object.
+
+Optionally, the data source can be specified by passing an open DBI database
+handle, or by passing the DBI data source name, username and password.
+
+If passed a DBI data source (or handle) such as `DBI:Pg:dbname=database', will
+use PostgreSQL-specific syntax. Non-standard syntax for other engines (if
+applicable) may also be supported in the future.
+
+If not passed a data source (or handle), or if there is no driver for the
+specified database, will attempt to use generic SQL syntax.
+
+=cut
+
+sub sql_alter_column {
+ my($self, $opt, $new, $dbh) = ( shift, _parse_opt(\@_), shift, _dbh(@_) );
+
+ my $table = $self->table_name;
+ die "$self: this column is not assigned to a table"
+ unless $table;
+
+ my $name = $self->name;
+
+ my $driver = $dbh ? _load_driver($dbh) : '';
+
+ my @sql = ();
+
+ my $dbd = "DBIx::DBSchema::DBD::$driver";
+ my $hashref = $dbd->alter_column_callback( $dbh, $table, $self, $new );
+
+ if ( $hashref->{'sql_alter'} ) {
+
+ push @sql, $hashref->{'sql_alter'};
+
+ } else {
+
+ # change the name...
+ # not yet implemented. how do we tell which old column it was?
+
+ # change the type...
+ if ( $hashref->{'sql_alter_type'} ) {
+ push @sql, $hashref->{'sql_alter_type'};
+ }
+
+ # change nullability...
+
+ if ( $hashref->{'sql_alter_null'} ) {
+
+ push @sql, $hashref->{'sql_alter_null'};
+
+ } else {
+
+ # change nullability from NOT NULL to NULL
+ if ( ! $self->null && $new->null ) {
+
+ push @sql, "ALTER TABLE $table ALTER COLUMN $name DROP NOT NULL";
+
+ }
+
+ # change nullability from NULL to NOT NULL...
+ # this one could be more complicated, need to set a DEFAULT value and update
+ # the table first...
+ if ( $self->null && ! $new->null ) {
+
+ push @sql, "ALTER TABLE $table ALTER COLUMN $name SET NOT NULL";
+
+ }
+
+ }
+
+ # change default
+ my $old_default = $self->quoted_default($dbh);
+ my $new_default = $new->quoted_default($dbh);
+ if ( $old_default ne $new_default ) {
+
+ my $alter = "ALTER TABLE $table ALTER COLUMN $name";
+
+ if ( $new_default ne '' ) {
+ #warn "changing from $old_default to $new_default\n";
+ push @sql, "$alter SET DEFAULT $new_default";
+ } elsif ( $old_default !~ /^nextval/i ) { #Pg-specific :(
+ push @sql, "$alter DROP DEFAULT";
+
+ push @sql, "UPDATE TABLE $table SET $name = NULL WHERE $name = ''"
+ if $opt->{'nullify_default'} && $old_default eq "''" && $new->null;
+ }
+
+ }
+
+ # change other stuff... (what next?)
+
+ }
+
+ @sql;
+
+}
+
+=item 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.
+
+=cut
+
+sub sql_drop_column {
+ my( $self, $dbh ) = ( shift, _dbh(@_) );
+
+ my $table = $self->table_name;
+ my $name = $self->name;
+
+ ("ALTER TABLE $table DROP COLUMN $name"); # XXX what about indexes???
+}
+
=back
=head1 AUTHOR
=head1 COPYRIGHT
-Copyright (c) 2000 Ivan Kohler
-Copyright (c) 2000 Mail Abuse Prevention System LLC
+Copyright (c) 2000-2006 Ivan Kohler
+Copyright (c) 2007-2010 Freeside Internet Services, Inc.
All rights reserved.
This program is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.
=head1 BUGS
-line() has database-specific foo that probably ought to be abstracted into
-the DBIx::DBSchema:DBD:: modules.
+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
=head1 SEE ALSO
projects / DBIx-DBSchema.git / blobdiff