ORACLE SQL DEVELOPER 的 MERGE / UPDATE 查询

Question

我有两个不同的表，table1 和 table2，如下所示

表1

LA_ID	ADDRESS	CITY	STATE
572	A1	C1	S1
300	A1	C1	S1
978	A1	C1	S1
082	A2	C2	S2
026	A2	C2	S2
093	A2	C2	S2

表2

LA_ID
572
572
300
300
978
978
978
978
082
082
082
026
026
093

我想更新 table2 LA_ID 的样子

LA_ID
572
572
572
572
572
572
572
572
082
082
082
082
082
082

基本上将table2的LA_ID更新为table1的LA_ID，其中ADDRESS、CITY和state是一样的。

我试过了

SET LA_ID = (SELECT new_LA_ID from (
(Select min(LA_ID) over
(partition by ADDRESS, city, state) as new_LA_ID,
LA_ID old_LA_ID
from table2 )) src
where src.old_LA_ID = tgt.LA_ID )
where tgt.LA_ID in (Select LA_ID old_LA_ID
from table2 
);

Answer 1

如果您愿意只使用最小值或最大值，您可以简单地使用update：

update table_2 t2
    set la_id = (select min(t1.la_id)
                 from table_1 t1 join
                      table_1 t12
                      on t1.state = t12.state and t1.city = t12.city and t1.address = t12.address
                 where t12.la_id = t2.la_id
                )
    where la_id <> (select min(t1.la_id)
                    from table_1 t1 join
                         table_1 t12
                         on t1.state = t12.state and t1.city = t12.city and t1.address = t12.address
                    where t12.la_id = t2.la_id
                   );

我不确定当存在重复项时，您是如何为您想要的特定 ID 选择 572 和 082。这将选择300 和026。