Postgres 10

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CREATE TABLE the_rule (
   value1 text NOT NULL
 , op1    text NOT NULL
 , value2 text NOT NULL
 , op2    text NOT NULL
);

INSERT INTO the_rule VALUES
   ('foo','=','bar','<')
 , ('baz','<','bam','>');

CREATE OR REPLACE FUNCTION rule_eval(_val text, _opr text, _arg text
                                   , OUT _pass bool) AS
$func$
BEGIN
   EXECUTE format('SELECT %L %s %L', _val, _opr, _arg)
   INTO _pass;
END
$func$  LANGUAGE plpgsql;
2 rows affected

SELECT rule_eval('1', '=', '1');


rule_eval


t


SELECT rule_eval('1', '=', '2');


rule_eval


f


SELECT * FROM the_rule
WHERE  rule_eval(value1, op1, 'foo')
AND    rule_eval(value2, op2, 'aaa');


value1
op1
value2
op2


baz
<
bam
>