如何在另一个表中的一个表中设置列数据Amazon Redshift

Question

I have this usecase where I have a table 'a', which has the same columns as table 'b'. What I want is: for all rows that are both in 'a' and 'b', I want 'a' to have the same value for column 'x' as 'b'.

Here is what I'm trying but I keep getting stuck:

UPDATE a 
   SET a.x = b.x 
   FROM b  INNER JOIN  a  ON a.id = b.id;

Im getting errors:

[Amazon](500310) Invalid operation: table name "a" specified more than once;

Any help would be greatly appreciated!

Answer 1

You are almost there just use below query

   UPDATE a 
   SET x = b.x 
   FROM b 
   where 
   a.id = b.id;

Answer 2

UPDATE a
   SET x = b.x
   FROM b
   where a.id = b.id;

This ended up working for me