SP2-0552:绑定变量"N3“未声明

Question

这是一个代码，用于比较三个数字并打印出最大的值。

declare
n1 number(2);
n2 number(2); 
n3 number(2); 
begin
n1:=&n1;
n2:=&n2:
n3:=&n3;
if n1>n2 and n1>n3 then
dbms_output.put_line('The greatest number is n1 '||n1);
else if n2>n1 and n2>n3 then
dbms_output.put_line('The greatest number is n2 '||n2);
else 
dbms_output.put_line('The greatest number is n3 '||n3);
end if;
end;
/

当我试图在oracle中运行这个pl sql代码时，它说：

old   6: n1:=&n1;
new   6: n1:=4;
Enter value for n2: 5
old   7: n2:=&n2:
new   7: n2:=5:
Enter value for n3: 6
old   8: n3:=&n3;
new   8: n3:=6;
SP2-0552: Bind variable "N3" not declared.

，你能告诉我哪里出了问题吗?我很感激

Answer 1

您有3个错误(键入)：

开始声明variables.

• n2:=&n2:之前需要DECLARE关键字的
• 应该是elsif (或者，如果您想保留else if，则需要第二个end if;来终止第二个if语句)

DECLARE
  n1 number(2);
  n2 number(2); 
  n3 number(2); 
begin
  n1:=&n1;
  n2:=&n2;
  n3:=&n3;
  if n1>n2 and n1>n3 then
    dbms_output.put_line('The greatest number is n1 '||n1);
  elsif n2>n1 and n2>n3 then
    dbms_output.put_line('The greatest number is n2 '||n2);
  else 
    dbms_output.put_line('The greatest number is n3 '||n3);
  end if;
end;
/