How to select all rows which have a field equal to {}

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My question was:

I see few rows like this in my table:

     id  | val
 --------+------------
    1    | {}
    2    | {}

Of course not all are equal to {}, and I would like to query them out and then update them to {0}. However, trying the following fails:

UPDATE table SET val={0} WHERE val={};

I must be missing something obvious, please point out what.

The answer, by user sandipon, was:

UPDATE table SET val='{0}' WHERE val='{}';