plsql 语法

 

-- 变量名 数据类型()
/*sales number(10, 2);*/
-- pi CONSTANT  DOUBLE precision(精度) :=3.1414926
/*pi CONSTANT double precision := 3.1415;
name varchar2(25);
address varchar2(100);*/
-- pi CONSTANT NUMBER := 3.141592654;


-- 编辑界面左上角有 SQL,输出,统计表三个标签，查看output要换到‘输出’的标签。

DECLARE
   -- constant declaration
   pi constant number := 3.141592654;
   -- other declarations
   radius number(5,2); 
   dia number(5,2); 
   circumference number(7, 2);
   area number (10, 2);
BEGIN 
   -- processing
   radius := 9.5; 
   dia := radius * 2; 
   circumference := 2.0 * pi * radius;
   area := pi * radius * radius;
   -- output
   dbms_output.put_line('Radius: ' || radius);
   dbms_output.put_line('Diameter: ' || dia);
   dbms_output.put_line('Circumference: ' || circumference);
   dbms_output.put_line('Area: ' || area);
END;
/



/*Diameter: 19
Circumference: 59.69
Area: 283.53Radius: 9.5*/


DECLARE
   a number(2) := 10;
BEGIN
   a:= 10;
  -- check the boolean condition using if statement 
   IF( a < 20 ) THEN
      -- if condition is true then print the following  
      dbms_output.put_line('a is less than 20 ' );
   END IF;
   dbms_output.put_line('value of a is : ' || a);
END;
/

/*a is less than 20 
value of a is : 10*/

DECLARE
   a number(2) := 30;
BEGIN
   a:= 30;
  -- check the boolean condition using if statement 
   IF( a < 20 ) THEN
      -- if condition is true then print the following  
      dbms_output.put_line('a is less than 20 ' );
   ELSE
     dbms_output.put_line('a is  greater  than 20 ' );
   END IF;
   dbms_output.put_line('value of a is : ' || a);
END;
/

DECLARE
   i number(1);
   j number(1);
BEGIN
   << outer_loop >>
   FOR i IN 1..3 LOOP
      << inner_loop >>
      FOR j IN 1..3 LOOP
         dbms_output.put_line('i is: '|| i || ' and j is: ' || j);
      END loop inner_loop;
   END loop outer_loop;
END;
/