how to setup LOCKS in ATL OELDB Consumer?

in sql server, we can use TABLOCK to lock a table, but how can i do this in ATL, without using a SP

i worry if two user perform db.Update() at the same time and refer to the same row, there may cause a problem.

i fond this line in the OLEDB ref.

Locking can occur with any of the methods that interact with rows on the data source. These include IRowsetLocate::GetRowsAt, IRowsetLocate::GetRowsByBookmark, IRowsetUpdate::Update, and others. These operations take locks and can wait for locks to be released by other transactions.

does this mean the locks are prefomed automatically ?

and, in the deferred update mode, if two user insert the same row into the DB, say, both of them insert 2 rows, 1 is the same, and the others are different, what would happen? what will the server return?

Locks are managed on the server side by the database engine.

Different cursor types (static, keyset or dynamic) and isolation levels can affect the server locking behavior. On the client, you can control cursor types and isolation level through OLEDB.

So the answer to the question regarding inserting the same row depends on the cursor type and iso level etc. If the table has an index that does not allow duplicate key, the 2nd insert could even fail. Basically, server will ensure transactional integrity is maintained for the data.

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so i learned the isolation levels, but what is a cursor type in OLEDB? i only heard that in ADO, do they have the same mean? and how can i set the cursor type in OLEDB

|||Cursor definition is the same across all API's. For ADO and ODBC, you can request a particular cursor type directly. OLEDB does this a bit differently, you request the behaviors of the cursor such as updatability, scrollabilty etc through the corresponding OLEDB properties, and OLEDB will find the most suitable cursor for you under the cover.