停留在 if 条件 (PL/SQL)

Question

我只想在满足'if'条件时执行三个或更多删除语句。

我有这个查询，它有几行，每一行都有一个名为last_update_date 的列。看看：

SELECT PRODUCT_ATTR         as CATEGORY,
       product_attr_val     as COD_CATEGORY,
       qer.last_update_date
  FROM qp_modifier qer
  JOIN qp_list qar ON qar.list_header_id = qer.list_header_id
 ORDER BY qer.last_update_date desc

我只想在last_update_date 的情况下执行这 3 个删除语句 从上面的查询等于实际的或实际上是前面的 天。

  delete from TABLE_PRODUCTS where product_id like 'WAL%';
  delete from TABLE_PRODUCTS where item_code like 'MAS%';
  delete from TABLE_PRODUCTS where customer_class_code='K' and customer_number is null;

我正在考虑做这样的事情：

  select max (last_update_date)
  into v_date
  from  qp_modifier

然后写下这样的语句：

  if v_date = sysdate  or v_date = sysdate - 1 then
      delete from TABLE_PRODUCTS where product_id like 'WAL%';
      delete from TABLE_PRODUCTS where item_code like 'MAS%';
      delete from TABLE_PRODUCTS where customer_class_code='K' and customer_number is null;
  end if;

但这对我来说没有多大意义。

你会如何修改它？

Answer 1

如果您使用or，您将拥有一个 delete：

delete from TABLE_PRODUCTS
where product_id like 'WAL%' or
      item_code like 'MAS%' or
      customer_class_code = 'K' ;

然后你可以包括你的附加存在条件：

delete from TABLE_PRODUCTS
where (product_id like 'WAL%' or
       item_code like 'MAS%' or
       customer_class_code = 'K'
      ) and
      (select max(qer.last_update_date)
       from qp_modifier qer join
            qp_list qar
            on qar.list_header_id = qer.list_header_id
      ) >= trunc(sysdate) - interval 1 day;

Answer 2

max() 函数不需要。满足 if 条件，前提是 存在 用于连接查询的任何行，且 qer.last_update_date 列值超过（或等于）当天之前：

delete table_products
 where (    upper(product_id) like 'WAL%'
         or upper(item_code) like 'MAS%'
         or ( upper(customer_class_code) = 'K' and nvl(customer_number,0)=0 ) )         
   and exists (
               select 1
                 from qp_modifier qer
                 join qp_list qar on qar.list_header_id = qer.list_header_id
                where qer.last_update_date >= systimestamp - interval '1' day )

在哪里适合使用upper() 以不区分大小写地包含与通配符模式匹配的所有数据。