Question

我在PL / SLQ功能中有以下情况。根据现有的表字段值，我可能会运行不同的选择。特别：对于特定的BILL CODE（PINGPONG），我可以有多行，我只需要获取SYS_FIELD值。根据以下条件，此字段只能获取一次：如果字段prep_seq_num = 0且primary_ind = 0，则只需直接获取此行sys_field值，并且不处理其他可能的prep_seq_num和不同于0的primary_ind值。如果该行不存在，则从prep_seq_num！= 0和primary_ind = 1中获取sys_field值。对于这两种情况，只能有一个实例/行。如果我有以下BILL表情况：

Tracking_ID  BSCO_CODE_ID  PREP_SEQ_NUM  ITEM_CAT_CODE_ID PRIMARY_IND SYS_FIELD
    1            PINGPONG        61             5               1        50
    2            PINGPONG        0              1               0        100

然后我应该从sys_field中获取值100，其中prep_seq_num = 0
所以在第一种情况下我应该运行：

SELECT SYS_FIELD
      INTO v_start_of_invoice
      FROM BILL
     WHERE TRACKING_ID = v_previous_trackingID
       AND BSCO_CODE_ID = 'PINGPONG'
       AND CHRG_ACCT_ID = v_ACCT_ID
       AND PREP_SEQ_NUM = 0 -- maybe not needed here
       AND ITEM_CAT_CODE_ID=1
       AND PARTITION_KEY = v_prev_partition
       AND SUBPARTITION_KEY = v_prev_subpartition
       AND PRIMARY_IND=0;

在第二种情况下，如果我实际上只有以下内容（prep_seq_num = 0不存在）

Tracking_ID  BSCO_CODE_ID  PREP_SEQ_NUM  ITEM_CAT_CODE_ID PRIMARY_IND SYS_FIELD
    1            PINGPONG        61             5               1        50

我应该从sys_field获取值50，因此运行以下查询：

SELECT SYS_FIELD
      INTO v_start_of_invoice
      FROM BILL
     WHERE TRACKING_ID = v_previous_trackingID
       AND BILL_CODE_ID = 'PINGPONG'
       AND ITEM_CAT_CODE_ID in ('5' , '-100')
       AND PARTITION_KEY = v_prev_partition
       AND SUBPARTITION_KEY = v_prev_subpartition
       AND PRIMARY_IND=1;

我有很多想法，但没有一个真正有效我希望在一个查询中获得最有效/最快速度。 THKS

Answer 1

您要寻找的是排名：您更喜欢prep_seq_num = 0 and primary_ind = 0而不是prep_seq_num <> 0 and primary_ind = 1。

执行此操作的典型方法是限制条款。这是标准SQL中的FETCH FIRST ROWS，可从Oracle 12c开始提供。另一种选择是ROW_NUMBER，它也是标准的SQL，自从我认为8i以来在Oracle中可用。

select sys_field
  into v_start_of_invoice
from bill
where tracking_id = v_previous_trackingid
  and bsco_code_id = 'PINGPONG'
  and partition_key = v_prev_partition
  and subpartition_key = v_prev_subpartition
  and 
  (
    (
      prep_seq_num = 0 and
      primary_ind = 0 and
      item_cat_code_id = 1 and
      chrg_acct_id = v_acct_id
    )
    or
    (
      prep_seq_num <> 0 and
      primary_ind = 1 and
      item_cat_code_id in (5, -100)
    )
  )
order by case when prep_seq_num = 0 then 1 else 2 end
fetch first 1 row only;

另一个选择是Oracle的KEEP FIRST：

select max(sys_field) keep (dense_rank first 
                            order by case when prep_seq_num = 0 then 1 else 2 end)
  into v_start_of_invoice
...

<击>

order by case when prep_seq_num = 0 then 1 else 2 end
fetch first 1 row only;

<击>

以下是ROW_NUMBER的查询：

select sys_field
  into v_start_of_invoice
from
(
  select 
    sys_field, 
    row_number() over (order by case when prep_seq_num = 0 then 1 else 2 end) as rn
  from bill
  where tracking_id = v_previous_trackingid
    and bsco_code_id = 'PINGPONG'
    and partition_key = v_prev_partition
    and subpartition_key = v_prev_subpartition
    and 
    (
      (
        prep_seq_num = 0 and
        primary_ind = 0 and
        item_cat_code_id = 1 and
        chrg_acct_id = v_acct_id
      )
      or
      (
        prep_seq_num <> 0 and
        primary_ind = 1 and
        item_cat_code_id in (5, -100)
      )
    )
)
where rn = 1;

PL / SQL - 如何根据表字段值运行不同的选择

1 个答案: