考慮到oracle中子表的值，更新父表

Question

我有表Parent_tbl，它由3列H_N，Col58和Type組成，前兩列將具有相同的值，只有列類型不同。

我有一個子表，其中col58定義了與父級的關係，但child_tbl中的其他列僅針對該表H_N是這兩個表中的唯一列。

我需要在PARENT_TBL中更新TYPE作爲EXCHANGE，當我發現CHILD_TBL I_STATUS具有像S，R和V的所有值，否則parent_tbl類型保持不變，我們該怎麼做？

Parent_tbl.col58 = 1140該類型應該是'EXCHANGE'，因爲child_tbl.col58 = 1140每個字母都是S，R，V。

這是樣品的DDL。

CREATE TABLE PARENT_TBL (
    H_N number, 
    col58 number, 
    TYPE varchar(100) 
); 
Insert into PARENT_TBL (H_N,COL58,TYPE) values (2,2,'SALE'); 
Insert into PARENT_TBL (H_N,COL58,TYPE) values (16,16,'SALE'); 
Insert into PARENT_TBL (H_N,COL58,TYPE) values (20,20,'SALE'); 
Insert into PARENT_TBL (H_N,COL58,TYPE) values (34,34,'VOID'); 
Insert into PARENT_TBL (H_N,COL58,TYPE) values (38,38,'SALE'); 
Insert into PARENT_TBL (H_N,COL58,TYPE) values (102,102,'SALE'); 
Insert into PARENT_TBL (H_N,COL58,TYPE) values (111,111,'SALE'); 
Insert into PARENT_TBL (H_N,COL58,TYPE) values (117,117,'SALE'); 
Insert into PARENT_TBL (H_N,COL58,TYPE) values (1140,1140,'RETURN'); 
Insert into PARENT_TBL (H_N,COL58,TYPE) values (131,131,'SALE'); 

commit; 

CREATE TABLE CHILD_TBL 
(
    I_STATUS varchar(100), 
    H_n number, 
    col58 number 
); 


Insert into CHILD_TBL (I_STATUS,H_N,COL58) values ('S',3,2); 
Insert into CHILD_TBL (I_STATUS,H_N,COL58) values ('S',5,2); 
Insert into CHILD_TBL (I_STATUS,H_N,COL58) values ('S',7,2); 
Insert into CHILD_TBL (I_STATUS,H_N,COL58) values ('S',8,2); 
Insert into CHILD_TBL (I_STATUS,H_N,COL58) values ('S',10,2); 
Insert into CHILD_TBL (I_STATUS,H_N,COL58) values ('S',1141,1140); 
Insert into CHILD_TBL (I_STATUS,H_N,COL58) values ('V',1142,1140); 
Insert into CHILD_TBL (I_STATUS,H_N,COL58) values ('R',1143,1140); 
Insert into CHILD_TBL (I_STATUS,H_N,COL58) values ('R',1144,1140); 
Insert into CHILD_TBL (I_STATUS,H_N,COL58) values ('S',1145,1140); 

commit; 

預期輸出：

truncate table PARENT_TBL ; 
    Insert into PARENT_TBL (H_N,COL58,TYPE) values (2,2,'SALE'); 
     Insert into PARENT_TBL (H_N,COL58,TYPE) values (16,16,'SALE'); 
     Insert into PARENT_TBL (H_N,COL58,TYPE) values (20,20,'SALE'); 
     Insert into PARENT_TBL (H_N,COL58,TYPE) values (34,34,'VOID'); 
     Insert into PARENT_TBL (H_N,COL58,TYPE) values (38,38,'SALE'); 
     Insert into PARENT_TBL (H_N,COL58,TYPE) values (102,102,'SALE'); 
     Insert into PARENT_TBL (H_N,COL58,TYPE) values (111,111,'SALE'); 
     Insert into PARENT_TBL (H_N,COL58,TYPE) values (117,117,'SALE'); 
     Insert into PARENT_TBL (H_N,COL58,TYPE) values (1140,1140,**'EXCHANGE'**); 
     Insert into PARENT_TBL (H_N,COL58,TYPE) values (131,131,'SALE'); 

Answer 1

使用此

update PARENT_TBL p 
set TYPE='EXCHANGE' 
where exists 
(select 1 
    from child_tbl c 
    where 
    i_status in ('S','R','V') 
    and c.col58=p.col58 
    group by col58 
    having count(distinct(i_status))=3 
) 

精通lanation：

select col58 
from child_tbl c 
where 
    i_status in ('S','R','V') 
    group by col58 
    having count(distinct(i_status))=3 

這將過濾後i_status in ('S','R','V')給你col58哪裏count(distinct(i_status))=3。因此，只有當'S','R','V'的每個狀態至少有1個時，纔會有3。現在在exists子句中使用此項並添加 a，其中條件在上述查詢中and c.col58=p.col58在更新時與parent表一起加入。

請首先嚐試這個測試數據，並嘗試這個，而不提交原始數據。只有當你確定你有預期的結果時才提交。

Answer 2

找到適當的分組在子表（CHILD_TBL）行和使用merge：

merge into parent_tbl p 
using (select col58 
     from child_tbl 
     group by col58 
     having count(decode(i_status, 'S', 1)) > 0 
      and count(decode(i_status, 'R', 1)) > 0 
      and count(decode(i_status, 'V', 1)) > 0) c 
on (p.col58 = c.col58) 
when matched then update set type = 'EXCHANGE'