Question

我需要编写一个postgres查询来获取beta_plan_id的集群ID并稍后进行一些操作..对于下表中的单个beta_plan_id，可能有许多merch id和很多cluster_id。这将如何处理??

BETA_PLAN_ID  MERCH_LEVEL1_ID    BETA_PLAN_MERCH_LVL1_CLSTR_ID    NO_OF_STORES
1                    1                 12                           5,6,7
1                    1                 13                            9,10
1                    1                 14                           2,3,4
2                    2                 15                            13,12

SELECT BETA_PLAN_MERCH_LVL1_CLSTR_ID INTO i_clstr_id 
FROM beta_plan.BETA_PLAN_MERCH_LVL1_CLSTR 
WHERE BETA_PLAN_ID = in_beta_plan_id;

问题是将返回许多结果，因为BETA_PLAN_MERCH_LVL1_CLSTR_ID是一个串行类型，并且为（beta_plan_id，merch_id，cluster_id）组合唯一生成。

SELECT BETA_PLAN_MERCH_LVL1_CLSTR_ID 
   INTO i_clstr_id 
   FROM beta_plan.BETA_PLAN_MERCH_LVL1_CLSTR 
   WHERE BETA_PLAN_ID = in_beta_plan_id;

INSERT INTO beta_plan.BETA_PLAN_MERCH_LVL1_CLSTR
   (
       BETA_PLAN_ID,
       MERCH_LEVEL1_ID,
       CLUSTER_ID,
       CLUSTER_NAME,
       NO_OF_STORES,
       NO_OF_FOOTAGE_VARIATION,
       CREATED_USER,
       CREATED_TS
   )
   SELECT 
      out_plan_id,
      merch_lvl1_clstr.MERCH_LEVEL1_ID,
      merch_lvl1_clstr.CLUSTER_ID,
      merch_lvl1_clstr.CLUSTER_NAME,
      merch_lvl1_clstr.NO_OF_STORES,
      merch_lvl1_clstr.NO_OF_FOOTAGE_VARIATION
      in_user_id, 
      now()
   FROM beta_plan.BETA_PLAN_MERCH_LVL1_CLSTR merch_lvl1_clstr
      INNER JOIN beta_plan.BETA_PLAN_MERCH_COPY_PLAN merch_copy
         ON merch_copy.MERCH_ID = merch_lvl1_clstr.MERCH_LEVEL1_ID
            AND merch_lvl1_clstr.BETA_PLAN_ID = in_beta_plan_id
   RETURNING BETA_PLAN_MERCH_LVL1_CLSTR_ID INTO o_clstr_id;

INSERT INTO beta_plan.BETA_PLAN_MERCH_LVL1_CLSTR_STR
   (
      BETA_PLAN_MERCH_LVL1_CLSTR_ID,
      STORE_ID,
      CREATED_USER,
      CREATED_TS         
   )
   SELECT 
      o_clstr_id,
      STORE_ID,     
      in_user_id, 
      now()
   FROM beta_plan.BETA_PLAN_MERCH_LVL1_CLSTR_STR
   WHERE BETA_PLAN_MERCH_LVL1_CLSTR_ID = i_clstr_id;

Answer 1

使用包含其他语句的SELECT循环代替第一个FOR语句：

FOR i_clstr_id IN
   SELECT BETA_PLAN_MERCH_LVL1_CLSTR_ID 
   FROM beta_plan.BETA_PLAN_MERCH_LVL1_CLSTR 
   WHERE BETA_PLAN_ID = in_beta_plan_id
LOOP
   /* your two INSERT statements come here */
END LOOP;

有关详细信息，请参阅the documentation。

需要一个针对postgres代码的for循环的建议

1 个答案: