Check whether the cursor returned a row or not; Process the record; Close the loop; Close the cursor; Cursor for loop simplifies the above steps by implicitly doing most of the above steps. Cursor for loop opens the cursor, iterates over the cursor and fetches the records from the cursor. Finally it closes the cursor. Cursor For Loop Example.
An implicit cursor FOR loop has a SELECT statement querying a table or a view instead of lower bound and upper bound values in the case of the traditional FOR loops. The cursor index of the FOR loop acts as a pointer to the result set processed by the associated SELECT statement in the private memory area known as the context area in the PGA. The cursor index points to each row and the period.
You can pass the values for the parameters of your cursor just by simply writing the argument right after the name of your cursor in loop statement as shown in the above example (Statement In bold). Always remember to enclose the arguments inside the parenthesis.
Cursor in SQL Server. Let's learn about Cursor in SQL Database with an example A cursor is a temporary work area created in the system memory, We normally loop through DML statement inside cursor, let’s look at the example below Before you write cursor, you need to know following few key characteristic about SQL Cursor. Declaring the Cursor.
Declaring Cursor A cursor is declared by defining the SQL statement. Opening Cursor A cursor is opened for storing data retrieved from the result set. Fetching Cursor When a cursor is opened, rows can be fetched from the cursor one by one or in a block to do data manipulation. Closing Cursor The cursor should be closed explicitly after data.
A Cursor For Loop implicitly declares its loop index as a record that represents a row fetched from the database. Next, it opens a cursor, repeatedly fetches rows of values from the result set into fields in the record, and then closes the cursor when all rows have been processed. Cursor For Loop Example DECLARE CURSOR c1 IS SELECT ename, sal.
If you are say doing maintenance, say a dbcc dbreindex on all tables in a database, then that is the defining quantity in your problem, and a cursor is imho, perfect for the job. As another for instance, I had a set based query, which sent a bunch of emails - probably should have been using notification servers, but you know how it is - a quarterly form that needed to be filled out and.
By Allen G. Taylor. To use a SQL cursor, you first must declare its existence to the DBMS. You do this with a DECLARE CURSOR statement. The DECLARE CURSOR statement doesn’t actually cause anything to happen; it just announces the SQL cursor’s name to the DBMS and specifies what query the cursor will operate on. A DECLARE CURSOR statement has the following syntax.