Mysql Syntax Error in Drupal 7 - drupal

Question

I am trying to define relationship between tables using foreign keys
in drupal 7. I used hook_schema and hook_update function to define and
update the schema. I am getting following errors.
$schema['relationship] = array(
'description' => 'The table for employee organisation relationship',
'fields' => array(
'rid' => array(
'description' => 'The primary Identifier for a Relationship.',
'type' => 'serial',
'unsigned' => TRUE,
'not null' => TRUE,
),
'uid' => array(
'description' => 'The primary Identifier for User/Employee',
'type' => 'int',
'unsigned' => TRUE,
'not null' => FALSE,
'default' => 0,
),
'oid' => array(
'description' => 'The department Identifier of employee employed',
'type' => 'int',
'unsigned' => TRUE,
'not null' => FALSE,
'default' => 0,
),
'indexes' => array(
'uid' => array('uid'),
'oid' => array('oid'),
),
'foreign keys' => array(
'uid' => array(
'table' => 'users',
'columns' => array('uid' => 'uid')
),
'oid' => array(
'table' => 'organization',
'columns' => array('oid' => 'oid')
),
),
'primary key' => array('rid'),
)
);
Failed: PDOException: SQLSTATE[42000]: Syntax error or access
violation: 1064 You have an error in your SQL syntax; check the manual
that corresponds to your MySQL server version for the right syntax to
use near 'DEFAULT NULL ) ENGINE = InnoDB DEFAULT CHARACTER SET utf8
COMMENT 'The table for' at line 5: CREATE TABLE
{organisation} ( id INT unsigned NOT NULL
auto_increment COMMENT 'The primary Identifier for a Relationship.',
uid INT unsigned NULL DEFAULT 0 COMMENT 'The primary Identifier for
User/Employee', oid INT unsigned NULL DEFAULT 0 COMMENT 'The
department Identifier of employee employed', primary key DEFAULT
NULL ) ENGINE = InnoDB DEFAULT CHARACTER SET utf8 COMMENT 'The table
for employee organisation relationship'; Array ( ) in
db_create_table() (line 2717 of
C:\xampp\htdocs\tutumaudit\includes\database\database.inc).

Answer 1

Well I sorted it out myself. I put those keys under the fields array.
That was damn stupid and i needed 2 hours to find this out. The final
code is below:
$schema['relationship] = array(
'description' => 'The table for employee organisation relationship',
'fields' => array(
'rid' => array(
'description' => 'The primary Identifier for a Relationship.',
'type' => 'serial',
'unsigned' => TRUE,
'not null' => TRUE,
),
'uid' => array(
'description' => 'The primary Identifier for User/Employee',
'type' => 'int',
'unsigned' => TRUE,
'not null' => FALSE,
'default' => 0,
),
'oid' => array(
'description' => 'The department Identifier of employee employed',
'type' => 'int',
'unsigned' => TRUE,
'not null' => FALSE,
'default' => 0,
),
),
'indexes' => array(
'uid' => array('uid'),
'oid' => array('oid'),
),
'foreign keys' => array(
'uid' => array(
'table' => 'users',
'columns' => array('uid' => 'uid')
),
'oid' => array(
'table' => 'organization',
'columns' => array('oid' => 'oid')
),
),
'primary key' => array('rid'),
);