def foreign_keys(table_name)
fk_info = select_all %Q{
SELECT fk.referenced_table_name as 'to_table'
,fk.referenced_column_name as 'primary_key'
,fk.column_name as 'column'
,fk.constraint_name as 'name'
FROM information_schema.key_column_usage fk
WHERE fk.referenced_column_name is not null
AND fk.table_schema = '#{@config[:database]}'
AND fk.table_name = '#{table_name}'
}
create_table_info = select_one("SHOW CREATE TABLE #{quote_table_name(table_name)}")["Create Table"]
fk_info.map do |row|
options = {:column => row['column'], :name => row['name'], :primary_key => row['primary_key']}
if create_table_info =~ %rCONSTRAINT #{quote_column_name(row['name'])} FOREIGN KEY .* REFERENCES .* ON DELETE (CASCADE|SET NULL|RESTRICT)/
options[:dependent] = case $1
when 'CASCADE' then :delete
when 'SET NULL' then :nullify
when 'RESTRICT' then :restrict
end
end
ForeignKeyDefinition.new(table_name, row['to_table'], options)
end
end