=head1 NAME

Class::AutoDB::Table - Schema information for one table

=head1 SYNOPSIS

This is a helper class for Class::AutoDB::Registry which represents the
schema information for one table.

 use Class::AutoDB::Table;
 my $table=new Class::AutoDB::Table
   (-name=>'Person',
    -keys{name=>'string',dob=>'integer',grade_avg=>'float',friend=>'object'});
 my $name=$table->name; 
 my $keys=$table->keys;           # hash of key=>type pairs
 my @sql=$table->schema;          # SQL statements to create table
 my @sql=$table->schema('create');# same as above
 my @sql=$table->schema('drop');  # SQL statements to drop table
 my @sql=$table->schema('alter'); # SQL statements to add columns 
                                  #   of this table to another

=head1 DESCRIPTION

This class represents schema information for one table. This class is
fed a HASH of key=E<gt>type pairs. Each turns into one column of the
table. In addition, the table has an 'object' column which is a foreign
key pointing to the AutoDB object table and which is the primary key
here. Indexes are defined on all keys (unless index=>0 is passed as an AutoDB 
constructor argument). This class just creates SQL; 
I<it does not talk to the database>.

At present, only our special data types ('string', 'integer', 'float',
'object') are supported. These can be abbreviated. These are translated
into MySQL types as follows:

 ----------------------------------
 | AutoDB type    | MySQL type    |
 ----------------------------------
 |  string        |  longtext     |
 |  integer       |  int          |
 |  float         |  double       |
 |  object        |  bigint       |
 |                | (unsigned)    |
 ----------------------------------

=cut