PLSQL Language Reference-PL/SQL语言基础-变量赋值-对BOOLEAN变量赋值

DECLARE

done BOOLEAN; — 默认的初始值为NULL

counter NUMBER := 0;

BEGIN

done := FALSE; — 用字面量赋值

WHILE done != TRUE — 与字面量比较

LOOP

counter := counter + 1;

done := (counter > 500); — 使用BOOLEAN类型的表达式的值赋值

END LOOP;

END;