postgresql ON CONFLICT with multiple constraints

问题

There is a constraint violation handling "On conflict" statement, working fine if i want to check 1 (!) constraint

For example :

 INSERT INTO my_table (co1,col2..colN) 
 VALUES (...) 
 ON CONFLICT (col1, col2) DO NOTHING --or update

But if i have 2 constaints unique(col1,col2) and unique(col5,col6,col7) , the query below is not working :

INSERT INTO my_table (co1,col2..colN) 
VALUES (...) 
ON CONFLICT (col1, col2) DO NOTHING --or update
ON CONFLICT (col5, col6, col7) DO NOTHING --or update

This raises the error, pointing on : ERROR: syntax error at or near "on". LINE _: on conflict (col5, col6, col7) do nothing

How could i resolve using multiple constraint checking in one query?

来源：https://stackoverflow.com/questions/52236263/postgresql-on-conflict-with-multiple-constraints