oracle语句的编译错误

我有下面的oracle语句，它给出了编译错误

v_percent_deceased_households := CASE
WHEN NVL(v_total_households, 0) > 0 THEN 
     (CAST(NVL(v_deceased_households_count, 0) AS FLOAT(53)) 
       / 
     CAST(NVL(v_total_households, 0) AS FLOAT(53))) * 100
   ELSE 0
      END;

错误包括：

错误：

PLS-00103: Encountered the symbol "(" when expecting one of the following:. ) @ %
       The symbol ")" was substituted for "(" to continue.
Line: 317
Text: (CAST(NVL(v_deceased_households_count, 0) AS FLOAT(53)) / CAST(NVL(v_total_households, 0) AS FLOAT(53))) * 100

Error: PLS-00103: Encountered the symbol "(" when expecting one of the following:. ) @ %
Line: 317
Text: (CAST(NVL(v_deceased_households_count, 0) AS FLOAT(53)) / CAST(NVL(v_total_households, 0) AS FLOAT(53))) * 100

我似乎无法解决此语法错误。

为什么强制转换（…作为浮点（53））？为什么不只是：

v_percent_deceased_households := CASE
WHEN v_total_households > 0 THEN 
     (NVL(v_deceased_households_count, 0) / v_total_households) * 100
   ELSE 0
      END;

---

（我也删除了一些多余的NVL）。

我认为必须在选择或“选择到”中使用CAST 例如 选择演员阵容（“2003年8月22日”为varchar2（30）） 来自双重

或 选择将（v_已故家庭_计数为浮动）转换为myfloat 来自双重