Re: How to use outer join in update

[Harald Fuchs <hf1110x@xxxxxxxxxxxxxx>]

In article <45792BC1.3040305@xxxxxxxxxxxxxxxxx>,
Alban Hertroys <alban@xxxxxxxxxxxxxxxxx> writes:

> Andrus wrote:
>> In my current DBMS I can use
>> 
>> create table t1 ( f1 int, f2 int );
>> create table t2 ( f3 int, f4 int );
>> update t1 set f1=t2.f3 from t1 left join t2 on  t1.f2=t2.f4

> That looks like a self-join on t1 without using an alias for the second
> instance of t1.

> I think you meant:
> update t1 set f1=t2.f3 from t2 where f2 = t2.f4

Or this one:

UPDATE t1
SET f1 = t2.f3
FROM t1 x
LEFT JOIN t2 ON x.f2 = t2.f4
WHERE x.f2 = t1.f2