必须声明标识符'input' - PL SQL

Question

每次我运行它并添加单词"黄色"或"红色"或"蓝色"时，都会出现相同的错误。

set serveroutput on
undefine color1
undefine color2
accept color1 prompt 'Type the 1st primary color: '
accept color2 prompt 'Type the 2nd primary color: '
begin
   if &color1 = &color2 then
      dbms_output.put_line(&color1||' plus '||&color2||' then '||&color1);
   elsif (&color1 = 'red' and &color2 = 'blue') or (&color2 = 'red' and &color1 = 'blue') then
      dbms_output.put_line(&color1||' plus '||&color2||' is purple');
   elsif (&color1 = 'red' and &color2 = 'yellow') or (&color2 = 'red' and &color1 = 'yellow') then
      dbms_output.put_line(&color1||' plus '||&color2||' is orange');
   else
      dbms_output.put_line(&color1||' plus '||&color2||' is green');
   end if;
end;
/   

错误：

ORA-06550: line 2, column 7:
PLS-00201: identifier 'BLUE' must be declared
ORA-06550: line 2, column 4:
PL/SQL: Statement ignored

请帮忙！:)

Answer 1

试试这样，

set serveroutput on
undefine color1
undefine color2
accept color1 prompt 'Type the 1st primary color: '
accept color2 prompt 'Type the 2nd primary color: '
BEGIN
   IF '&color1' = '&color2' THEN
      dbms_output.put_line('&color1'||' plus '||'&color2'||' then '||'&color1');
   elsif ('&color1' LIKE 'red' AND '&color2' LIKE 'blue') OR ('&color2' LIKE 'red' AND '&color1' LIKE 'blue') THEN
      dbms_output.put_line('&color1'||' plus '||'&color2'||' is purple');
   elsif ('&color1' LIKE 'red' AND '&color2' LIKE 'yellow') OR ('&color2' LIKE 'red' AND '&color1' LIKE 'yellow') THEN
      dbms_output.put_line('&color1'||' plus '||'&color2'||' is orange');
   ELSE
      dbms_output.put_line('&color1'||' plus '||'&color2'||' is green');
   end if;
END;
/   

或者最好将color1和color2存储在这样的局部变量中，

SET serveroutput ON
undefine color1
undefine color2
accept color1 prompt 'Type the 1st primary color: '
accept color2 prompt 'Type the 2nd primary color: '
DECLARE 
   color_1 VARCHAR2(10) := '&color1';
   color_2 VARCHAR2(10) := '&color2';
BEGIN
   IF color_1 = color_2 THEN
      dbms_output.put_line(color_1||' plus '||color_2||' then '||color_1);
   elsif (color_1 LIKE 'red' AND color_2 LIKE 'blue') OR (color_2 LIKE 'red' AND color_1 LIKE 'blue') THEN
      dbms_output.put_line(color_1||' plus '||color_2||' is purple');
   elsif (color_1 LIKE 'red' AND color_2 LIKE 'yellow') OR (color_2 LIKE 'red' AND color_1 LIKE 'yellow') THEN
      dbms_output.put_line(color_1||' plus '||color_2||' is orange');
   ELSE
      dbms_output.put_line(color_1||' plus '||color_2||' is green');
   END IF;
end;

Answer 2

&color1是一个

替换变量，sqlplus 基本上用用户输入内容替换了&color1 - 这里必须是单引号文字。只要不是，您的blue输入就会被视为未定义的变量名称。

因此，您有两种选择 - 要么在 sqlplus 中输入带引号的 'blue' 、'yellow' 等，要么在代码中将&color1替换为 '&color1'。

Answer 3

试试这个

 set serveroutput on
    undefine color1
    undefine color2
    accept color1 prompt 'Type the 1st primary color: '
    accept color2 prompt 'Type the 2nd primary color: '
    begin
       if '&color1' = '&color2' then
          dbms_output.put_line('&color1'||' plus '||'&color2'||' then '||'&color1');
       elsif ('&color1' like 'red' and '&color2' like 'blue') or ('&color2' like 'red' and '&color1' like 'blue') then
          dbms_output.put_line('&color1'||' plus '||'&color2'||' is purple');
       elsif ('&color1' like 'red' and '&color2' like 'yellow') or ('&color2' like 'red' and '&color1' like 'yellow') then
          dbms_output.put_line('&color1'||' plus '||'&color2'||' is orange');
       else
          dbms_output.put_line('&color1'||' plus '||'&color2'||' is green');
       end if;
    end;
    /