Take n multiple table names of a database as the values of a column in another table (the range can be a table in another database)

Demand scenarios

First check to see if it matches

select * from ouo o 
INNER JOIN information_schema.TABLES t on INSTR(t.table_name,o.key)
where table_schema='wewe'

Find that it can match , In the next step, you can batch modify

update ouo o INNER JOIN information_schema.TABLES t on INSTR(t.table_name,o.key)
set o.username=t.table_name
where table_schema='wewe'

The results are as follows

Mainly MYSQL INSTR Function function , You can search for MYSQL String contains attempts to write more