以下のsqlスクリプトは、未分類のものを「実際の」信用格付けに更新します。私はこれが役立つことを願っています
CREATE TABLE #WorkTable
(
InstrID INT,
CountryName VARCHAR(50),
CreditRating VARCHAR(20)
)
INSERT INTO #WorkTable VALUES (1, 'UK','AA');
INSERT INTO #WorkTable VALUES (2, 'UK','Unclassified');
INSERT INTO #WorkTable VALUES (3, 'South Africa','A');
INSERT INTO #WorkTable VALUES (4, 'South Africa','A');
INSERT INTO #WorkTable VALUES (5, 'South Africa','Unclassified');
WITH cteUnclassified
AS
(
SELECT InstrID,
CountryName,
CeditRating
FROM #WorkTable
WHERE CreditRating != 'Unclassified'
)
UPDATE #WorkTable
SET CreditRating = u.CreditRating
FROM #WorkTable wt
INNER JOIN cteUnclassified u
ON wt.CountryName = u.CountryName
WHERE wt.CreditRating = 'Unclassified'
SELECT *
FROM #WorkTable
以下のクエリの結果:
InstrID COUNTRYNAME信用格付け 1英国AA 2英国AA 3南アフリカA 4南アフリカA 5南アフリカA