Day 84 – Cursors
These are database objects that allow you to traverse through the result set of a query one row at a time. Cursors can be useful when you need to perform complex processing on each row of a result set.
DECLARE @CustomerID INT DECLARE @CustomerName VARCHAR(50) DECLARE customer_cursor CURSOR FOR SELECT CustomerID, CustomerName FROM Customers OPEN customer_cursor FETCH NEXT FROM customer_cursor INTO @CustomerID, @CustomerName WHILE @@FETCH_STATUS = 0 BEGIN PRINT 'Customer ID: ' + CAST(@CustomerID AS VARCHAR(10)) + ', Name: ' + @CustomerName FETCH NEXT FROM customer_cursor INTO @CustomerID, @CustomerName END CLOSE customer_cursor DEALLOCATE customer_cursor
In this example, a cursor named
customer_cursor is used to retrieve the
CustomerName from the
Customers table. The cursor is then used in a loop to print out the ID and name of each customer.