Application for Locking

[zhinokin]

HI..does anyone would like to suggest what application should i develop that could i apply a Locking ..any useful application.

i already read about this topic and i find it interesting and id like it to be my thesis..

Hope you can help me to this...

[sknake]

Lock what? A file? A license key to "lock" the application after a demo period expired?

I don't understand what you are asking...

[zhinokin]

in databse ...lock tables or pages, rows..like that..
any web applications where i can apply this locking method .

[sknake]

Develop an invoicing system with customers and line items for sale. Lock the table while the invoice is being updated. Here is a sample customer table (MSSQL):

IF OBJECT_ID('Test123', 'U') IS NOT NULL DROP Table Test123
Create Table Test123
(
  Name varchar(20) PRIMARY KEY,
)
GO
Insert Into Test123 (Name) Values ('Scott')
GO

BEGIN TRANSACTION
Update Test123 WITH (TABLOCKX,HOLDLOCK) Set Name = 'abc'

Select *
From Test123 WITH (TABLOCKX,HOLDLOCK)
waitfor delay '00:01:30'

--Go do something in another query.. the table cant be accessed without (NOLOCK)

COMMIT

[zhinokin]

tnx for the suggestion...can you please expound more about the invoicing system you suggest..

is mssql is much better to use than mysql...? coz for my 2 yrs in database field im using mysql and never use an mssql...and just want to know if mssql is best use for locking..

can you explain line 11 -14..i just dont able to get it well...
i think my understanding is different..i just want to know the correct understanding of it..

BTW..thanks for this..now i have an application to propose...

[sknake]

Why are you concentrating on locking so much? What lines 11-14 does it request a table lock on Test123 and other connections/transactions cannot access the table since it is locked until the txn completes. I added the delay in there so you would have 30 seconds to try to access the table but they will all hang up until the locking txn completes.

[zhinokin]

im trying to solve concurrency control in database..thats why i always ask question about locking..

and if i understand so much about locking ill make it as my thesis..

but if you have some suggestions about thesis topic it would be a great help ..