即使排除参数，内连接也会返回更多结果

Question

我的执行查询是：

SELECT rrr.extern_OD_id,
   rrr.refund_it_amount,
   rrr.refund_amount,
   rrr.invoice_ref_7,
   rrr.invoice_total_amount
FROM
(SELECT return.extern_OD_id,
      return.refund_it_amt AS refund_it_Amount,
                              return.refund_amount,
                              billing_tbl.invoice_ref_7,
                              billing_tbl.invoice_total_amount
FROM
 (SELECT rrrf.extern_OD_id,
         sum(rrrf.refund_it_amt) AS refund_it_amt,
         sum(rrrf.refund_amount/100)   refund_amount
  FROM rrr__refunds_fact rrrf
  WHERE rrrf.refund_status = 'completed'
    AND rrrf.refund_created_date_key >= '20150401'
    AND rrrf.refund_mode IN('CREDIT_CARD',
                            'CREDIT_EMI',
                            'DDCHEQUE',
                            'DEBIT_CARD',
                            'GIFT_VOUCHER',
                            'ICICI',
                            'NETBANKING',
                            'back_to_source')
    AND rrrf.refund_mode NOT IN ('GIFT_Card')
    GROUP BY rrrf.extern_OD_id) RETURN
LEFT JOIN
 (SELECT invoice_ref_7,
         sum(invoice_total_amount) invoice_total_amount
  FROM invoice_fact
  WHERE invoice_type_key = 'receiv_note'
    AND invoice_status_key NOT IN('voided',
                                  'canceled',
                                  'cancelled')
 GROUP BY invoice_ref_7) billing_tbl ON RETURN.extern_OD_id =billing_tbl.invoice_ref_7
WHERE RETURN.refund_amount <> billing_tbl.invoice_total_amount
 OR billing_tbl.invoice_ref_7 IS NULL) rrr
WHERE rrr.refund_it_amount >0
AND rrr.refund_amount >0

但是当我尝试加入另一个表并排除一些参数时，它给了我比表srrr_refunds_fact中的记录更多的记录。 它提供了来自新连接表的许多记录，即在rrr__refunds_fact中不存在的Payment_TBL。 你能告诉我哪里出错了。 根据我的理解，如果第一个查询返回n个记录，则在加入新记录之后应该是n或者＆lt; Ñ

SELECT rrr.extern_OD_id,
   rrr.refund_it_amount,
   rrr.refund_amount,
   rrr.invoice_ref_7,
   rrr.invoice_total_amount
FROM
(SELECT return.extern_OD_id,
      return.refund_it_amt AS refund_it_Amount,
                              return.refund_amount,
                              billing_tbl.invoice_ref_7,
                              billing_tbl.invoice_total_amount
FROM
 (SELECT rrrf.extern_OD_id,
         sum(rrrf.refund_it_amt) AS refund_it_amt,
         sum(rrrf.refund_amount/100)   refund_amount
  FROM rrr__refunds_fact rrrf
  JOIN Payment_TBL paymt ON paymt.payment_ref_num_2 = rrrf.extern_OD_id
  WHERE rrrf.refund_status = 'completed'
    AND rrrf.refund_created_date_key >= '20150401'
    AND rrrf.refund_mode IN('CREDIT_CARD',
                            'CREDIT_EMI',
                            'DDCHEQUE',
                            'DEBIT_CARD',
                            'GIFT_VOUCHER',
                            'ICICI',
                            'NETBANKING',
                            'back_to_source')
    AND rrrf.refund_mode NOT IN ('GIFT_Card')
    AND paymt.payment_method_key NOT IN ('WALLET')
    AND paymt.payment_ref_num_4 NOT IN ('PRICE_REFUND')
   GROUP BY rrrf.extern_OD_id) RETURN
LEFT JOIN
 (SELECT invoice_ref_7,
         sum(invoice_total_amount) invoice_total_amount
  FROM invoice_fact
  WHERE invoice_type_key = 'receiv_note'
    AND invoice_status_key NOT IN('voided',
                                  'canceled',
                                  'cancelled')
 GROUP BY invoice_ref_7) billing_tbl ON RETURN.extern_OD_id =billing_tbl.invoice_ref_7
WHERE RETURN.refund_amount <> billing_tbl.invoice_total_amount
 OR billing_tbl.invoice_ref_7 IS NULL) rrr
WHERE rrr.refund_it_amount >0
AND rrr.refund_amount >0