Concat text from old database/table and insert in a new/differente database/table

UPDATE 
database1.table1 AS table1

SET table1.new_column = (
 SELECT group_concat(old_column SEPARATOR ' ') AS 'old_column'
 FROM database2.table2 as table2
 WHERE table2.id = table1.id
 GROUP BY table2.id
)

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