11.7.11. FOR Select Statement

<for statement> ::=
     FOR <query exp> DO statement

The FOR statement provides a compact notation for iterating over the result set of a cursor. The body is executed once for each row in the query expression's result set. The result columns produced by the query expression are accessible as variables of the same name inside the body. All result columns do therefore have to be named with the AS declaration if they are not simple columns, in which case the name defaults to the column's name.

The body can be exited in mid loop with a goto. The cursor of the FOR does not have to be specifically closed or opened. FOR statements can be freely nested. If a WHENEVER NOT FOUND declaration is in effect before the FOR it will be canceled by it, so that it is not in effect after the loop's body.

Example 11.2. Examples

for select C_NAME, sum (O_VALUE) as value  from CUSTOMER, ORDER group by C_NAME DO
    result (C_NAME, value);

The equivalent code is

declare C_NAME, value any;
whenever not found goto done;
declare cr cursor for select ....;
open cr;
while (1) {
  fetch cr into C_NAME, value;
  whenever not found default;
done: ;

The cursor and end label names are generated to be unique by the FOR expansion.