修改价格属性转换

app/Casts/Price.php

@@ -17,6 +17,10 @@ class Price implements CastsAttributes
      */
     public function get($model, string $key, $value, array $attributes)
     {
+        if ((string) $value === '') {
+            return null;
+        }
+
         return bcdiv($value, 100, 2);
     }
 
@@ -31,6 +35,10 @@ class Price implements CastsAttributes
      */
     public function set($model, string $key, $value, array $attributes)
     {
+        if ((string) $value === '') {
+            return null;
+        }
+
         return (int) bcmul($value, 100);
     }
 }