Table row id's are not getting updated after delecting the row in the grid table view.

[sense red]

HI Everyone,

I am facing one issue regarding the database table row.id.

my db:

db.define_table('testcases',Field('Testcase_Name',requires=IS_NOT_EMPTY()),
                Field('Time_stamp','datetime',requires=IS_NOT_EMPTY()))

controller:

def testcases():
    form = SQLFORM(db.testcases).process()
    grid = SQLFORM.smartgrid(db.testcases)
    return locals()

problem is :

I have inserted 10 rows into "testcase" table and i have deleted the 5th row from the table, then the row ids has to display(1,2,3,4,5,6,7,8,9) but it was displaying as (1,2,3,4,6,7,8,9,10).

Please help me to resolve this issue.