合计字段为空时进行处理

applications/commons/commons-dto/src/main/java/com/usoftchina/saas/commons/dto/ListReqDTO.java

@@ -38,7 +38,7 @@ public class ListReqDTO implements Serializable {
                         fieldSql = new StringBuilder("'{");
                         fieldSql.append("\"" + field + "\":'");
                         fieldSql.append(",");
-                        fieldSql.append(operation + "(" + field + ")");
+                        fieldSql.append("ifnull(" + operation + "(" + field + ")" + ",'0')");
                         fieldSql.append(",");
                         fieldSql.append("',\"operation\":\"" + operation + "\"");
                         fieldSql.append("}'");