plsql - 使用 PLSQL 时，此 SELECT 语句中需要 INTO 子句

Question

我收到以下错误。在 SELECT CASE 语句处收到错误。

PLS-00428: an INTO clause is expected in this SELECT statement

FOR REMS IN cur_names LOOP

SELECT CASE   
        WHEN EXISTS (SELECT 1 
                     FROM SupplyTable 
                     WHERE FirstName = REMS.Names) 
        THEN 'Y' 
        ELSE 'N' 
    END AS rec_exists
FROM dual;

  IF rec_exists = 'Y' THEN
    FName := REMS.Names;
  ELSE
    FName := 'Gen';
  END IF;
END LOOP;

Answer 1

您不能在 pl sql 代码中进行随机选择。它必须位于带有 into 子句的循环、游标中。只需在此处包含一个 into 子句即可。

declare 
   v_value varchar2(1);
begin
...
FOR REMS IN cur_names LOOP

   SELECT CASE   
           WHEN EXISTS (SELECT 1 
                        FROM SupplyTable 
                        WHERE FirstName = REMS.Names) 
           THEN 'Y' 
           ELSE 'N' 
       END AS rec_exists
   INTO v_value 
   FROM dual;
   IF v_value = 'Y' THEN
      FName := REMS.Names;
   ELSE
      FName := 'Gen';
   END IF;
END LOOP;
...

或循环

FOR REMS IN cur_names LOOP

   for i in 
   (   
       SELECT CASE   
           WHEN EXISTS (SELECT 1 
                        FROM SupplyTable 
                        WHERE FirstName = REMS.Names) 
           THEN 'Y' 
           ELSE 'N' 
       END AS rec_exists
       FROM dual
   )
   loop
      IF i.rec_exists = 'Y' THEN
         FName := REMS.Names;
      ELSE
         FName := 'Gen';
     END IF;
   end loop;
END LOOP;