Question

如果有人可以提供帮助，那就太好了。我编写了以下查询，但除非我使用distinct，否则返回多行。使用distinct它可以按预期工作，但没有它非常慢并返回许多行。

SELECT distinct ('RCT' || rt.transaction_id) Unique_Receipt_Source_ID,
                hla.location_code warehouse_code,
                    iwm.whse_name warehouse_name,
                pvs.vendor_site_id vendor_site_id,
                pvs.vendor_site_code vendor_site_name,
                pha.vendor_id,
                v.vendor_name,
                pha.segment1 po_num,
                pla.attribute4 container,
                pla.attribute5 fill_level,
                pha.fob_lookup_code inco_terms,
                iwi.fixed_leadtime,
                pla.line_num po_line_num,
                iim.item_no item_no,
                rt.transaction_date receipt_date,
                rt.quantity Receipt_quantity,
                rt.unit_of_measure Receipt_UOM,
                rt.currency_code Receipt_Currency_Code,
                (rt.quantity * pla.unit_price) receipt_amount,
                pla.unit_price PO_Unit_price,
                iim.item_desc1 item_description,
                pla.item_description po_line_description,
                pha.terms_id SYS_pay_terms_id,
                ap.name pay_terms_name,
                ap.description pay_terms_description,
                papf.full_name BUYER,
                plla.country_of_origin_code country_of_origin,
                (pla.quantity * pla.unit_price) PO_LINE_AMOUNT,
                pha.currency_code PO_currency_code,
                pla.quantity PO_LINE_QTY,
                pla.unit_meas_lookup_code PO_LINE_UOM
  FROM po_headers_all pha,
       po_line_locations_all plla,
       po_lines_all pla,
       apps.po_vendor_sites_all pvs,
       apps.po_vendors v,
       rcv_transactions rt,
       apps.ic_whse_inv iwi,
       apps.ic_whse_mst iwm,
       apps.ic_item_mst iim,
       apps.per_all_people_f papf,
       apps.hr_locations_all hla,
       ap_terms ap,
       mtl_system_items_b msi
WHERE  pha.po_header_id = pla.po_header_id
       AND plla.po_header_id = pha.po_header_id
       AND papf.person_id = pha.agent_id
       AND pha.vendor_id = v.vendor_id
       AND pha.vendor_site_id = pvs.vendor_site_id
       AND v.vendor_id = pvs.vendor_id
       AND pla.po_header_id = pha.po_header_id
       AND iim.item_no = msi.segment1 
       and msi.inventory_item_id = pla.item_id    
       and iwi.item_id = iim.item_id   
       AND rt.po_header_id = pha.po_header_id
       AND hla.location_id = pha.ship_to_location_id
       AND rt.po_line_id = pla.po_line_id
       AND iwm.whse_code = iwi.whse_code
       AND hla.location_code = iwi.whse_code      
       AND pha.terms_id = ap.term_id
       AND rt.transaction_type = 'RECEIVE'       
       order by pha.segment1, pla.line_num;

Answer 1

此查询是ANSI连接语法优于隐式连接语法的一个很好的示例。 ANSI连接语法强制您一次构建一个结果集。保持表及其谓词靠近使得语句更容易理解和调试。

原始查询需要记住数十个项目才能理解其中的任何一项。新语法需要了解集合，新表以及将其添加到集合的新谓词;重复这些步骤，直到查询完成。

下面的重写查询显示了ANSI连接语法的一些更具体的好处。当强制命令谓词时，很明显其中一个谓词被重复。该谓词是无意义的重复还是缺失条件的错字？将此语法与现代IDE相结合，可以快速找到错误;突出显示一个集合，运行它，检查结果，将下一个表格和谓词添加到突出显示，运行它，检查结果;重复这些步骤，直到找到错误。

  SELECT *
    FROM po_headers_all pha
    JOIN po_line_locations_all plla
      ON pha.po_header_id = plla.po_header_id
    JOIN po_lines_all pla
      ON pha.po_header_id = pla.po_header_id
     AND pha.po_header_id = pla.po_header_id --Repeated predicate - typo?
    JOIN apps.po_vendor_sites_all pvs
      ON pha.vendor_site_id = pvs.vendor_site_id
    JOIN apps.po_vendors v
      ON pha.vendor_id = v.vendor_id
     AND pvs.vendor_id = v.vendor_id
    JOIN rcv_transactions rt
      ON pla.po_line_id = rt.po_line_id
     AND pha.po_header_id = rt.po_header_id
     AND rt.transaction_type = 'RECEIVE' --Not a join, but may be helpful here.
    JOIN apps.hr_locations_all hla
      ON pha.ship_to_location_id = hla.location_id
    JOIN apps.ic_whse_inv iwi
      ON hla.location_code = iwi.whse_code
    JOIN apps.ic_whse_mst iwm
      ON iwi.whse_code = iwm.whse_code
    JOIN mtl_system_items_b msi
      ON pla.item_id = msi.inventory_item_id
    JOIN apps.ic_item_mst iim
      ON msi.segment1 = iim.item_no
     AND iwi.item_id = iim.item_id
    JOIN apps.per_all_people_f papf
      ON pha.agent_id = papf.person_id
    JOIN ap_terms ap
      ON pha.terms_id = ap.term_id
ORDER BY pha.segment1, pla.line_num;

Oracle 11i SQL导致多行返回

1 个答案: