Friday, October 17, 2008

Cursors in SQL:

Cursors in SQL:

A cursor is a database object that help in naccessing and manupulating data in given result set.
The main advantage is that we can process the data row-by -row.

There are four types cursors.

1. Static:

It alwys displays the result set as it was when the cursor opened.
statis cursors are always read-only.

2. Dynamic:
Dynamic cursors are opposite of static cursors.It refers all changes made to the rows in their result set when scrolling through the cursor.

3. Forward- Only:
The forward - only cursors does not support ; it supports
only frtching the rows serially from the start to end of the cursors.

4.Keyset-driven:
The keyset is the set of key values from all the rows that
qualified for the slect statement at the time the cursor was opened.

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