如何使用 EXISTS 关键字判断两个表中是否存在相同记录？

select *
from temp1
where exists (
    select *
    from temp2
    where temp1.pn_code = temp2.pn_code
    and temp1.serialnumber = temp2.serialnumber
);

SELECT *
FROM (
    SELECT pn_Code, serialNumber
    FROM pnassertbasic_ruku pr
    LEFT JOIN pnassertruku pu ON pr.parent_pnAssertRuku_id = pu.child_pnAssertRukuDetails_id
    WHERE pn_Code IS NOT NULL
    AND serialNumber IS NOT NULL
    AND DATE(pr.create_time) = CURDATE()
    AND pr.warehouseEntryNumber <> 'WEd3791f0b'
) AS temp1
WHERE EXISTS (
    SELECT *
    FROM (
        SELECT pn_Code, serialNumber
        FROM pnassertbasic_ruku pr
        LEFT JOIN pnassertruku pu ON pr.parent_pnAssertRuku_id = pu.child_pnAssertRukuDetails_id
        WHERE pu.child_pnAssertRukuDetails_id IS NULL
        AND pr.warehouseEntryNumber = 'WEd3791f0b'
    ) AS temp2
    WHERE temp1.pn_Code = temp2.pn_Code
    AND temp1.serialNumber = temp2.serialNumber
);