mysql - 使用 case 函数合并 2 个 SELECT 查询

Question

我的第一个查询是:

SELECT c.icareno, c.operation_date, p.prod_cat_name, prod.product_name, c.nename,
       c.operation_desc, u.uname, c.oper_severity, c.rfc_status 
  FROM ccb c, product_cat p, userlogininfo u, productname prod 
 WHERE c.prod_cat = p.prod_cat_id 
   AND c.prod_id = prod.prod_id 
   AND c.oper_leader = u.userid 
   AND c.ccb_id <= 279
ORDER BY c.operation_date;

第二个查询是

SELECT c.icareno, c.operation_date, p.prod_cat_name, prod.product_name, node.node_name, 
       c.operation_desc, u.uname, c.oper_severity, c.rfc_status 
  FROM ccb c, product_cat p, userlogininfo u, productname prod, node_list node
 WHERE c.prod_cat = p.prod_cat_id 
   AND c.prod_id = prod.prod_id 
   AND c.oper_leader = u.userid 
   AND c.ccb_id > 279 
   AND c.nename = node.node_id
ORDER BY c.operation_date;

我想使用 CASE 函数合并这两个查询？谁能帮助我如何合并它？

示例数据:

Answer 1

and ((c.ccb_id > 279 AND c.nename =    node.node_id) or c.ccb_id <= 279)