What is cursors?

What is cursors?
Cursor is a database object used by applications to manipulate data in a set on a row-by-row basis,
instead of the typical SQL commands that operate on all the rows in the set at one time.

In order to work with a cursor we need to perform some steps in the following order:
Declare cursor
Open cursor
Fetch row from the cursor
Process fetched row
Close cursor
Deallocate cursor

Comments

Post a Comment

Popular posts from this blog

What is the use of DBCC commands?

What is the use of DBCC commands? DBCC stands for database consistency checker. We use these commands to check the consistency of the databases, i.e., maintenance, validation task and status checks. E.g. DBCC CHECKDB - Ensures that tables in the db and the indexes are correctly linked. DBCC CHECKALLOC - To check that all pages in a db are correctly allocated. DBCC CHECKFILEGROUP - Checks all tables file group for any damage.
Read more

Google to FTS Syntax Cheat Sheet

Image
OPERATOR EXAMPLE DESCRIPTION   nut Searches for inflectional forms of the word nut crank arm crank AND arm Searches for documents containing inflectional forms of the words crank AND arm crank and ann. The keyword AND is optional. tire OR air Searches for documents containing inflectional forms of the words tire or air, “reflector bracket” Performs a phrase search for the phrase "reflector bracket". hardware -bracket Searches for documents containing inflectional forms of the word hardware but not the word bracket. +clamp Searches for the word darn') without generating inflectional forms. ~seat Searches for thesaurus forms of the word seat Assemb* Searches for words that begin with the prefix assemb . <washer nut> Searches for documents that contain the words washer in close proximity to the word nut
Read more

What is difference between DELETE and TRUNCATE commands?

Delete command removes the rows from a table based on the condition that we provide with a WHERE clause. Truncate will actually remove all the rows from a table and there will be no data in the table after we run the truncate command. TRUNCATE : TRUNCATE is faster and uses fewer system and transaction log resources than DELETE. TRUNCATE removes the data by deallocating the data pages used to store the table's data, and only the page deallocations are recorded in the transaction log. TRUNCATE removes all rows from a table, but the table structure, its columns, constraints, indexes and so on, remains. The counter used by an identity for new rows is reset to the seed for the column. You cannot use TRUNCATE TABLE on a table referenced by a FOREIGN KEY constraint. Because TRUNCATE TABLE is not logged, it cannot activate a trigger. TRUNCATE cannot be rolled back. TRUNCATE is DDL Command. TRUNCATE Resets identity of the table DELETE : DELETE removes rows one at a time...
Read more