PL/SQL用户自定义子类型操作

 -- Created on 2018/3/21 by E.WANG

    
 /*
    
 使用subtype用定义子类型
    
 */
    
 declare 
    
    subtype userName is char(20);
    
    subtype sex is char(6);
    
    uName userName;
    
    userSex sex;
    
 begin
    
    uName := 'ewang ';
    
    userSex := 'male';
    
    dbms_output.put_line('user name:' || uName || 'Sex: ' || userSex);
    
   
    
 end;