在DB2中，基于大量行的插入执行更新

Question

In DB2, I need to do an insert, then, using results/data from that insert, update a related table. I need to do it on a million plus records and would prefer not to lock the entire database. So, 1) how do I 'couple' the insert and update statements? 2) how can I ensure the integrity of the transaction (without locking the whole she-bang)?

some pseudo-code should help clarify

STEP 1

 insert into table1 (neededId, id)        select DYNAMICVALUE, id from tableX      where needed value is null

STEP 2

 update table2 set neededId = (GET THE DYNAMIC VALUE JUST INSERTED)     where id = (THE ID JUST INSERTED)

note: in table1, the ID col is not unique, so i can't just filter on that to find the new DYNAMICVALUE

This should be more clear (FTR, this works, but I don't like it, because I'd have to lock the tables to maintain integrity. Would be great it I could run these statements together, and allow the update to refer to the newAddressNumber value.)

/****RUNNING TOP INSERT FIRST****/*

--insert a new address for each order that does not have a address id
insert into addresses
    (customerId, addressNumber, address)    
select 
    cust.Id, 
    --get next available addressNumber
    ifNull((select max(addy2.addressNumber) from addresses addy2 where  addy2.customerId = cust.id),0) + 1 as newAddressNumber,
    cust.address
from customers cust
where exists (
    --find all customers with at least 1 order where addressNumber is null
    select 1 from orders ord
    where 1=1
    and ord.customerId = cust.id
    and ord.addressNumber is null   
    )


/*****RUNNING THIS UPDATE SECOND*****/          
update orders ord1
set addressNumber = (
            select max(addressNumber) from addresses addy3 
            where addy3.customerId = ord1.customerId
            ) 
where 1=1 
    and ord1.addressNumber is null  

Answer 1

IDENTITY_VAL_LOCAL函数是一个不确定性函数，它返回标识列的最新分配值，该赋值是由于使用VALUES子句的单个INSERT语句而发生的