SQL合併兩個選擇具有不同列號的查詢，同時刪除重複項？

Question

使用SQL Server，我有Where子句的兩個Select語句，但不斷得到重複的結果。我的第一個查詢是：

SELECT 
    PricingContingencies.*, 
    Terms.*, 
    rscDescription AS RateScheme, 
    ptyAbbreviation AS PointTypeAbbreviation, 
    FAKs.*, 
    fat.* 
    FROM ((((PricingContingencies 
    INNER JOIN Terms ON pcoTerms = terID) 
    INNER JOIN PointTypes ON pcoPointTypeFK = ptyID) 
    LEFT JOIN RateSchemes ON pcoRateSchemeFK = rscID) 
    LEFT JOIN FAKs ON fakPricingContingencyFK = pcoID) 
    LEFT JOIN FuelAgreementTypes fat ON ftyID = pcoFuelAgreementTypeFK 
    WHERE pcoPricingAgreementFK = 61523 and pcoID = 16490608 

並返回兩行（這是正確的）。

我的第二個查詢非常相似，但有附加列（唯一的區別是 'LEFT JOIN PalletPricing ON pprPricingContingenciesFK = pcoID）' 而不是 'LEFT JOIN電傳ON fakPricingContingencyFK = pcoID）'：

SELECT 
    PricingContingencies.*, 
    Terms.*, 
    rscDescription as RateScheme, 
    ptyAbbreviation as PointTypeAbbreviation, 
    PalletPricing.*, 
    fat.* 
FROM ((((PricingContingencies 
    INNER JOIN Terms ON pcoTerms = terID) 
    INNER JOIN PointTypes ON pcoPointTypeFK = ptyID) 
    LEFT JOIN RateSchemes ON pcoRateSchemeFK = rscID) 
    LEFT JOIN PalletPricing ON pprPricingContingenciesFK = pcoID) 
    LEFT JOIN FuelAgreementTypes fat ON ftyID = pcoFuelAgreementTypeFK 
WHERE pcoPricingAgreementFK = 61523 and pcoID = 16490608 

而且返回6行（這也是正確的）。

我該如何合併它們才能獲得8行總計？如果我使用將它們組合起來的INNER JOIN像：

SELECT 
    FirstSet.*, 
    SecondSet.* 
FROM (
    SELECT 
    PricingContingencies.*, 
    Terms.*, 
    rscDescription AS RateScheme, 
    ptyAbbreviation AS PointTypeAbbreviation, 
    FAKs.*, 
    fat.* 
    FROM ((((PricingContingencies 
    INNER JOIN Terms ON pcoTerms = terID) 
    INNER JOIN PointTypes ON pcoPointTypeFK = ptyID) 
    LEFT JOIN RateSchemes ON pcoRateSchemeFK = rscID) 
    LEFT JOIN FAKs ON fakPricingContingencyFK = pcoID) 
    LEFT JOIN FuelAgreementTypes fat ON ftyID = pcoFuelAgreementTypeFK 
    WHERE pcoPricingAgreementFK = 61523 and pcoID = 16490608 
) as FirstSet 
INNER JOIN 
    (
    SELECT 
     PricingContingencies.*, 
     Terms.*, 
     rscDescription as RateScheme, 
     ptyAbbreviation as PointTypeAbbreviation, 
     PalletPricing.*, 
     fat.* 
    FROM ((((PricingContingencies 
     INNER JOIN Terms ON pcoTerms = terID) 
     INNER JOIN PointTypes ON pcoPointTypeFK = ptyID) 
     LEFT JOIN RateSchemes ON pcoRateSchemeFK = rscID) 
     LEFT JOIN PalletPricing ON pprPricingContingenciesFK = pcoID) 
     LEFT JOIN FuelAgreementTypes fat ON ftyID = pcoFuelAgreementTypeFK 
    WHERE pcoPricingAgreementFK = 61523 and pcoID = 16490608 
    ) as SecondSet 
ON FirstSet.pcoID = SecondSet.pcoID 
ORDER BY FirstSet.pcoPriority DESC 

我得到12行，其中PalletPricing列被複制和不正確（第二結果加倍[6×2]）。我如何組合它們，以便得到正確的8行（2 + 6）？

在此先感謝。

Answer 1

對於你想要的INNER JOIN將無法​​正常工作。使用像當前代碼一樣的連接會將每個查詢中的所有列填充到非常寬的行中。您需要UNION（不是UNION ALL，因爲它專門用於而不是檢查dups）。

由於您收到的評論中提到您必須在每個查詢中具有相同數量的字段，並且它們應該包含等效數據，否則根據它們來自哪個查詢，您的字段將具有兩種不同類型的數據。

當使用UNION時，明確指定您的字段也是一個好主意，.*是一種冒險的方式，因爲您打賭所有列在相關表格中的排列順序相同。所以，你可以這樣做：

SELECT 
    rscDescription AS RateScheme, 
    ptyAbbreviation AS PointTypeAbbreviation, 
    FROM ((((PricingContingencies 
    INNER JOIN Terms ON pcoTerms = terID) 
    INNER JOIN PointTypes ON pcoPointTypeFK = ptyID) 
    LEFT JOIN RateSchemes ON pcoRateSchemeFK = rscID) 
    LEFT JOIN FAKs ON fakPricingContingencyFK = pcoID) 
    LEFT JOIN FuelAgreementTypes fat ON ftyID = pcoFuelAgreementTypeFK 
    WHERE pcoPricingAgreementFK = 61523 and pcoID = 16490608 
UNION 
SELECT 
     rscDescription as RateScheme, 
     ptyAbbreviation as PointTypeAbbreviation, 
    FROM ((((PricingContingencies 
     INNER JOIN Terms ON pcoTerms = terID) 
     INNER JOIN PointTypes ON pcoPointTypeFK = ptyID) 
     LEFT JOIN RateSchemes ON pcoRateSchemeFK = rscID) 
     LEFT JOIN PalletPricing ON pprPricingContingenciesFK = pcoID) 
     LEFT JOIN FuelAgreementTypes fat ON ftyID = pcoFuelAgreementTypeFK 
    WHERE pcoPricingAgreementFK = 61523 and pcoID = 16490608 

這僅僅是爲你的兩個字段匹配明顯的例子，你必須去列逐列。

Answer 2

你必須把「union all」而不是inner join。

SELECT 
    PricingContingencies.*, 
    Terms.*, 
    rscDescription AS RateScheme, 
    ptyAbbreviation AS PointTypeAbbreviation, 
    FAKs.*, 
    fat.* 
    FROM ((((PricingContingencies 
    INNER JOIN Terms ON pcoTerms = terID) 
    INNER JOIN PointTypes ON pcoPointTypeFK = ptyID) 
    LEFT JOIN RateSchemes ON pcoRateSchemeFK = rscID) 
    LEFT JOIN FAKs ON fakPricingContingencyFK = pcoID) 
    LEFT JOIN FuelAgreementTypes fat ON ftyID = pcoFuelAgreementTypeFK 
    WHERE pcoPricingAgreementFK = 61523 and pcoID = 16490608 
union all 
    SELECT 
     PricingContingencies.*, 
     Terms.*, 
     rscDescription as RateScheme, 
     ptyAbbreviation as PointTypeAbbreviation, 
     PalletPricing.*, 
     fat.* 
    FROM ((((PricingContingencies 
     INNER JOIN Terms ON pcoTerms = terID) 
     INNER JOIN PointTypes ON pcoPointTypeFK = ptyID) 
     LEFT JOIN RateSchemes ON pcoRateSchemeFK = rscID) 
     LEFT JOIN PalletPricing ON pprPricingContingenciesFK = pcoID) 
     LEFT JOIN FuelAgreementTypes fat ON ftyID = pcoFuelAgreementTypeFK 
    WHERE pcoPricingAgreementFK = 61523 and pcoID = 16490608