Column Aliases in Cursors

The SELECT statement of the cursor includes the list of columns that are returned by that cursor. Just as with any SELECT statement, this column list may contain either actual column names or column expressions, which are also referred to as calculated or virtual columns.

A column alias is an alternative name you provide to a column or column expression in a query. You may have used column aliases in SQL*Plus in order to improve the readability of ad hoc report output. In that situation, such aliases are completely optional. In an explicit cursor, on the other hand, column aliases are required for calculated columns when:

· You FETCH into a record declared with a %ROWTYPE declaration against that cursor.
· You want to reference the calculated column in your program.

DECLARE
CURSOR comp_cur IS
SELECT company_name, SUM (inv_amt) total_sales
FROM company C, invoice I
WHERE C.company_id = I.company_id
AND I.invoice_date BETWEEN '01−JAN−1994' AND '31−DEC−1994';
comp_rec comp_cur%ROWTYPE;
BEGIN
OPEN comp_cur;
FETCH comp_cur INTO comp_rec;
...
END;