1. 合并 firstname, lastname.
1: declare
2: v_first_name varchar2(255);
3: v_last_name varchar2(255);
4: begin
5: select first_name, last_name
6: into v_first_name, v_last_name
7: from student
8: where student_id = 777;
9:
10: dbms_output.put_line('Student Name: ' || v_first_name || ' ' || v_last_name);
11: exception
12: when no_data_found then
13: dbms_output.put_line('There is no data');
14: end;
15: /
16: show errors;
2. 使用替代变量, 交互内容, 个人感觉替代变量并不常用, 真正生产情况时, 那有那么多人来输入替代变量的值啊.
/* * 测试替代变量 * sv_student_id, sv 个人理解是 system value的意思 */ declare v_student_id number := &sv_student_id; v_first_name varchar2(255); v_last_name varchar2(255); begin select first_name, last_name into v_first_name, v_last_name from student where student_id = &sv_student_id; dbms_output.put_line('Student Name: ' || v_first_name || '' || v_last_name); exception when no_data_found then dbms_output.put_line('There is no student'); end; / show errors;
注意: 运行以上例子2 时, 系统会给出提示, 让你输入 student_id 的值, 然后会显示 old_value, new_value