CASE

最新推荐文章于 2024-11-03 14:53:03 发布

weixin_30517001

最新推荐文章于 2024-11-03 14:53:03 发布

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CC 4.0 BY-SA版权

原文链接：http://www.cnblogs.com/David-Huang/archive/2013/04/02/2995528.html

简单的CASE语句

1 case expression
2   when result1 then
3     statement1
4   when result2 then
5     statement2
6   ...
7   else 
8     statement_else
9 end case;

1 case people --变量
2   when 'Chinese' then
3     dbms_output.put_line('你好！');
4   when 'Spanish' then
5     dbms_output.put_line('hola');
6   else 
7     dbms_output.put_line(q'(s'up)');
8 end case;

搜索型CASE语句

1 case --(true)
2   when expression1 then
3        statement1
4   when expression2 then
5        statement2
6   ...     
7   else 
8     statement_else
9 end case;

 1 declare
 2   v_score number := 100;
 3 begin
 4   case
 5     when v_score > 90 then
 6       dbms_output.put_line('A');
 7     when v_score > 80 then
 8       dbms_output.put_line('B');
 9     when v_score > 70 then
10       dbms_output.put_line('C');
11     when v_score > 60 then
12       dbms_output.put_line('D');
13     else
14       dbms_output.put_line('E');
15   end case;
16 end;

CASE表达式

1 declare
2   people varchar2(10) := '天朝人';
3 begin
4   dbms_output.put_line(case people
5                          when '天朝人' then '你好' 
6                          when 'Spanish' then 'hola' 
7                          else q'(s'up)' 
8                          end);
9 end;

 1 declare
 2   v_score number := 100;
 3 begin
 4   dbms_output.put_line(case
 5                           when v_score > 90 then 'A' 
 6                           when v_score > 80 then 'B' 
 7                           when v_score > 70 then 'C' 
 8                           when v_score > 60 then 'D' 
 9                           else 'E' 
10                           end);
11 end;