CREATE TABLE t1 (c1 INT PRIMARY KEY, c2 INT )

CREATE TABLE t2 (c1 INT PRIMARY KEY, c2 INT )

ALTER TABLE t1 ADD CONSTRAINT t1t2FK FOREIGN KEY (c2) REFERENCES t2(c1)

ALTER...

insert into ##temptable

select relevant.columns

from table1 inner join table2 on pk1 = pk2

where table1.createdate = yesterday

and (table1.col1 <> table2.col1 or

table1.col2 <> table2.col2 or

...