Konvertierung von VARCHAR -Daten in datetime fehlschlägen
https://dba.stackexchange.com/questions/5312
-
16-10-2019 - |
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Wir sind dabei, Daten aus einer Legacy -Tabelle (alle VARCHAR -Felder) in ein stark typisiertes Gegenstück zu bewegen Cue Jubel
Im Rahmen dieser Bemühungen nehmen wir Daten aus der Basientabelle und lassen sie in entity_new ein, wenn alle Daten korrekt in den entsprechenden Typ konvertiert werden können. Andernfalls wird in eine Kopie der vorhandenen Tabelle mit dem Namen entity_bad eingeleitet.
Wir haben eine Rules -Engine, die die Daten und Typen wie diese theoretisch validiert hat. Die Daten sollten sauber sein, obwohl sie in Charakterfeldern gespeichert sind. Die Realität ist mein Posten hier, weil etwas ausgeschaltet ist und ich es nicht finden kann. Das Fertigstellungsfeld in der Entität ist varchar (46) null
Umwelt ist
productversion productlevel edition
10.0.4064.0 SP2 Enterprise Edition (64-bit)
Meine Skripte zeigen, was ich tat und was ist, aber nicht funktioniert
SET NOCOUNT ON
DECLARE
@startid int = 0
, @stopid int = 796833
-------------------------------------------------------------------------------
-- Check doesn't find anything wrong with CompletionDate
-------------------------------------------------------------------------------
SELECT
1
FROM
[dbo].[Entity] E
INNER JOIN
dbo.EntityBatch_New PB
ON E.FiscalYear = PB.FiscalYear
AND E.HashCode = PB.HashCode
AND E.AAKey = PB.AAKey
AND PB.ProcessResultCode IN ('A','W','M')
WHERE
PB.EntityBatchId BETWEEN @StartId AND @StopId
AND
(
-- check
(isDate(E.[CompletionDate]) = 0 AND E.[CompletionDate] IS NOT NULL)
AND (isDate(E.[CompletionDate]) = 1 AND CAST(E.[CompletionDate] AS datetime) BETWEEN '1753-01-01T00:00:00.000' AND '9999-12-31T23:59:59.997')
)
-------------------------------------------------------------------------------
-- Only row that shows as non-date is the NULL one, which is expected
-------------------------------------------------------------------------------
SELECT DISTINCT
(E.[CompletionDate] )
, isDate(E.[CompletionDate])
FROM
[dbo].[Entity] E
INNER JOIN
dbo.EntityBatch_New PB
ON E.FiscalYear = PB.FiscalYear
AND E.HashCode = PB.HashCode
AND PB.ProcessResultCode IN ('A','W','M')
-- Ensure we aren't pulling something we have already processed
LEFT OUTER JOIN
[dbo].[Entity_new] N
ON N.HashCode = E.HashCode
AND N.FiscalYear = E.FiscalYear
AND E.AAKey = N.AAKey
-- Ensure we aren't pulling something we have already processed (or was bad)
LEFT OUTER JOIN
[dbo].[Entity_bad] BAD
ON BAD.HashCode = E.HashCode
AND BAD.FiscalYear = E.FiscalYear
AND E.AAKey = BAD.AAKey
WHERE
PB.EntityBatchId BETWEEN @StartId AND @StopId
AND N.FiscalYear IS NULL
AND BAD.FiscalYear IS NULL
ORDER BY 2
-------------------------------------------------------------------------------
-- Make the cast and it blows with
-- The conversion of a varchar data type to a datetime data type resulted in an out-of-range value.
-------------------------------------------------------------------------------
SELECT DISTINCT
(E.[CompletionDate] )
, CAST(E.[CompletionDate] AS datetime) AS [CompletionDate]
FROM
[dbo].[Entity] E
INNER JOIN
dbo.EntityBatch_New PB
ON E.FiscalYear = PB.FiscalYear
AND E.HashCode = PB.HashCode
AND PB.ProcessResultCode IN ('A','W','M')
-- Ensure we aren't pulling something we have already processed
LEFT OUTER JOIN
[dbo].[Entity_new] N
ON N.HashCode = E.HashCode
AND N.FiscalYear = E.FiscalYear
AND E.AAKey = N.AAKey
-- Ensure we aren't pulling something we have already processed (or was bad)
LEFT OUTER JOIN
[dbo].[Entity_bad] BAD
ON BAD.HashCode = E.HashCode
AND BAD.FiscalYear = E.FiscalYear
AND E.AAKey = BAD.AAKey
WHERE
PB.EntityBatchId BETWEEN @StartId AND @StopId
AND N.FiscalYear IS NULL
AND BAD.FiscalYear IS NULL
-------------------------------------------------------------------------------
-- Dump the values into a temporary table to slice and dice the values
-------------------------------------------------------------------------------
DECLARE @debug TABLE
(
CompletionDate varchar(46) NULL
)
INSERT INTO
@debug
SELECT DISTINCT
(E.[CompletionDate] )
FROM
[dbo].[Entity] E
INNER JOIN
dbo.EntityBatch_New PB
ON E.FiscalYear = PB.FiscalYear
AND E.HashCode = PB.HashCode
AND PB.ProcessResultCode IN ('A','W','M')
-- Ensure we aren't pulling something we have already processed
LEFT OUTER JOIN
[dbo].[Entity_new] N
ON N.HashCode = E.HashCode
AND N.FiscalYear = E.FiscalYear
AND E.AAKey = N.AAKey
-- Ensure we aren't pulling something we have already processed (or was bad)
LEFT OUTER JOIN
[dbo].[Entity_bad] BAD
ON BAD.HashCode = E.HashCode
AND BAD.FiscalYear = E.FiscalYear
AND E.AAKey = BAD.AAKey
WHERE
PB.EntityBatchId BETWEEN @StartId AND @StopId
AND N.FiscalYear IS NULL
AND BAD.FiscalYear IS NULL
-------------------------------------------------------------------------------
-- This is operating on all the same values as the failing query but magically works
-------------------------------------------------------------------------------
SELECT ALL
CAST(E.[CompletionDate] AS datetime) AS [CompletionDate]
FROM
@debug E
-------------------------------------------------------------------------------
-- Clearly, something is amiss when we extract the data so process each row
-- and find the culprit that way. Except this finds nothing wrong
-------------------------------------------------------------------------------
DECLARE @hash uniqueidentifier
, @zee_date varchar(46)
, @real_date datetime
DECLARE
CSR CURSOR READ_ONLY
FOR
SELECT
E.HashCode
, E.[CompletionDate]
FROM
[dbo].[Entity] E
INNER JOIN
dbo.EntityBatch_New PB
ON E.FiscalYear = PB.FiscalYear
AND E.HashCode = PB.HashCode
AND PB.ProcessResultCode IN ('A','W','M')
-- Ensure we aren't pulling something we have already processed
LEFT OUTER JOIN
[dbo].[Entity_new] N
ON N.HashCode = E.HashCode
AND N.FiscalYear = E.FiscalYear
AND E.AAKey = N.AAKey
-- Ensure we aren't pulling something we have already processed (or was bad)
LEFT OUTER JOIN
[dbo].[Entity_bad] BAD
ON BAD.HashCode = E.HashCode
AND BAD.FiscalYear = E.FiscalYear
AND E.AAKey = BAD.AAKey
WHERE
PB.EntityBatchId BETWEEN @StartId AND @StopId
AND N.FiscalYear IS NULL
AND BAD.FiscalYear IS NULL
OPEN CSR
FETCH NEXT FROM CSR INTO
@hash, @zee_date
WHILE (@@fetch_status = 0)
BEGIN
BEGIN TRY
SELECT @real_date = cast(@zee_date AS datetime)
END TRY
BEGIN CATCH
print 'In here'
print @hash
print @zee_date
SELECT @hash, @zee_date
END CATCH
FETCH NEXT FROM CSR INTO
@hash, @zee_date
END
CLOSE csr
DEALLOCATE csr
Nachdem Sie Sie mit der obigen Code -Wand mit der Code -Wand kritisiert haben, sind hier die 406 eindeutigen Werte, auf denen die oben genannten Abfragen arbeiten.
DECLARE @REAL_DATES TABLE
(
CompletionDate varchar(46) NULL
)
INSERT INTO
@REAL_DATES
SELECT
NULL
UNION ALL SELECT '19000101'
UNION ALL SELECT '20100208'
UNION ALL SELECT '20100228'
UNION ALL SELECT '20100309'
UNION ALL SELECT '20100314'
UNION ALL SELECT '20100401'
UNION ALL SELECT '20100409'
UNION ALL SELECT '20100420'
UNION ALL SELECT '20100427'
UNION ALL SELECT '20100429'
UNION ALL SELECT '20100507'
UNION ALL SELECT '20100615'
UNION ALL SELECT '20100617'
UNION ALL SELECT '20100629'
UNION ALL SELECT '20100701'
UNION ALL SELECT '20100703'
UNION ALL SELECT '20100704'
UNION ALL SELECT '20100706'
UNION ALL SELECT '20100709'
UNION ALL SELECT '20100713'
UNION ALL SELECT '20100714'
UNION ALL SELECT '20100715'
UNION ALL SELECT '20100716'
UNION ALL SELECT '20100720'
UNION ALL SELECT '20100721'
UNION ALL SELECT '20100726'
UNION ALL SELECT '20100727'
UNION ALL SELECT '20100728'
UNION ALL SELECT '20100729'
UNION ALL SELECT '20100731'
UNION ALL SELECT '20100801'
UNION ALL SELECT '20100802'
UNION ALL SELECT '20100803'
UNION ALL SELECT '20100804'
UNION ALL SELECT '20100807'
UNION ALL SELECT '20100809'
UNION ALL SELECT '20100810'
UNION ALL SELECT '20100811'
UNION ALL SELECT '20100813'
UNION ALL SELECT '20100817'
UNION ALL SELECT '20100819'
UNION ALL SELECT '20100820'
UNION ALL SELECT '20100822'
UNION ALL SELECT '20100823'
UNION ALL SELECT '20100825'
UNION ALL SELECT '20100827'
UNION ALL SELECT '20100828'
UNION ALL SELECT '20100830'
UNION ALL SELECT '20100831'
UNION ALL SELECT '20100901'
UNION ALL SELECT '20100902'
UNION ALL SELECT '20100904'
UNION ALL SELECT '20100907'
UNION ALL SELECT '20100908'
UNION ALL SELECT '20100909'
UNION ALL SELECT '20100910'
UNION ALL SELECT '20100911'
UNION ALL SELECT '20100913'
UNION ALL SELECT '20100916'
UNION ALL SELECT '20100919'
UNION ALL SELECT '20100920'
UNION ALL SELECT '20100922'
UNION ALL SELECT '20100923'
UNION ALL SELECT '20100925'
UNION ALL SELECT '20100928'
UNION ALL SELECT '20101002'
UNION ALL SELECT '20101004'
UNION ALL SELECT '20101007'
UNION ALL SELECT '20101009'
UNION ALL SELECT '20101010'
UNION ALL SELECT '20101013'
UNION ALL SELECT '20101016'
UNION ALL SELECT '20101018'
UNION ALL SELECT '20101019'
UNION ALL SELECT '20101020'
UNION ALL SELECT '20101022'
UNION ALL SELECT '20101023'
UNION ALL SELECT '20101025'
UNION ALL SELECT '20101028'
UNION ALL SELECT '20101030'
UNION ALL SELECT '20101102'
UNION ALL SELECT '20101107'
UNION ALL SELECT '20101108'
UNION ALL SELECT '20101109'
UNION ALL SELECT '20101111'
UNION ALL SELECT '20101112'
UNION ALL SELECT '20101114'
UNION ALL SELECT '20101117'
UNION ALL SELECT '20101119'
UNION ALL SELECT '20101124'
UNION ALL SELECT '20101126'
UNION ALL SELECT '20101127'
UNION ALL SELECT '20101129'
UNION ALL SELECT '20101201'
UNION ALL SELECT '20101203'
UNION ALL SELECT '20101204'
UNION ALL SELECT '20101206'
UNION ALL SELECT '20101209'
UNION ALL SELECT '20101210'
UNION ALL SELECT '20101213'
UNION ALL SELECT '20101214'
UNION ALL SELECT '20101215'
UNION ALL SELECT '20101216'
UNION ALL SELECT '20101220'
UNION ALL SELECT '20101222'
UNION ALL SELECT '20101227'
UNION ALL SELECT '20101228'
UNION ALL SELECT '20101229'
UNION ALL SELECT '20101230'
UNION ALL SELECT '20110102'
UNION ALL SELECT '20110103'
UNION ALL SELECT '20110104'
UNION ALL SELECT '20110106'
UNION ALL SELECT '20110107'
UNION ALL SELECT '20110108'
UNION ALL SELECT '20110109'
UNION ALL SELECT '20110110'
UNION ALL SELECT '20110111'
UNION ALL SELECT '20110114'
UNION ALL SELECT '20110116'
UNION ALL SELECT '20110118'
UNION ALL SELECT '20110119'
UNION ALL SELECT '20110120'
UNION ALL SELECT '20110122'
UNION ALL SELECT '20110123'
UNION ALL SELECT '20110125'
UNION ALL SELECT '20110126'
UNION ALL SELECT '20110128'
UNION ALL SELECT '20110130'
UNION ALL SELECT '20110203'
UNION ALL SELECT '20110205'
UNION ALL SELECT '20110206'
UNION ALL SELECT '20110208'
UNION ALL SELECT '20110210'
UNION ALL SELECT '20110212'
UNION ALL SELECT '20110213'
UNION ALL SELECT '20110215'
UNION ALL SELECT '20110218'
UNION ALL SELECT '20110221'
UNION ALL SELECT '20110224'
UNION ALL SELECT '20110226'
UNION ALL SELECT '20110301'
UNION ALL SELECT '20110302'
UNION ALL SELECT '20110304'
UNION ALL SELECT '20110307'
UNION ALL SELECT '20110309'
UNION ALL SELECT '20110311'
UNION ALL SELECT '20110314'
UNION ALL SELECT '20110316'
UNION ALL SELECT '20110317'
UNION ALL SELECT '20110320'
UNION ALL SELECT '20110321'
UNION ALL SELECT '20110323'
UNION ALL SELECT '20110326'
UNION ALL SELECT '20110328'
UNION ALL SELECT '20110329'
UNION ALL SELECT '20110331'
UNION ALL SELECT '20110403'
UNION ALL SELECT '20110405'
UNION ALL SELECT '20110406'
UNION ALL SELECT '20110408'
UNION ALL SELECT '20110410'
UNION ALL SELECT '20110415'
UNION ALL SELECT '20110416'
UNION ALL SELECT '20110417'
UNION ALL SELECT '20110418'
UNION ALL SELECT '20110421'
UNION ALL SELECT '20110422'
UNION ALL SELECT '20110423'
UNION ALL SELECT '20110426'
UNION ALL SELECT '20110429'
UNION ALL SELECT '20110501'
UNION ALL SELECT '20110503'
UNION ALL SELECT '20110504'
UNION ALL SELECT '20110506'
UNION ALL SELECT '20110508'
UNION ALL SELECT '20110509'
UNION ALL SELECT '20110511'
UNION ALL SELECT '20110512'
UNION ALL SELECT '20110514'
UNION ALL SELECT '20110517'
UNION ALL SELECT '20110518'
UNION ALL SELECT '20110519'
UNION ALL SELECT '20110520'
UNION ALL SELECT '20110522'
UNION ALL SELECT '20110526'
UNION ALL SELECT '20110531'
UNION ALL SELECT '20110603'
UNION ALL SELECT '20110604'
UNION ALL SELECT '20110605'
UNION ALL SELECT '20110606'
UNION ALL SELECT '20110608'
UNION ALL SELECT '20110611'
UNION ALL SELECT '20110613'
UNION ALL SELECT '20110614'
UNION ALL SELECT '20110616'
UNION ALL SELECT '20110622'
UNION ALL SELECT '20110624'
UNION ALL SELECT '20110627'
UNION ALL SELECT '20110703'
UNION ALL SELECT '20110704'
UNION ALL SELECT '20110711'
UNION ALL SELECT '20110712'
UNION ALL SELECT '20110713'
UNION ALL SELECT '20110714'
UNION ALL SELECT '20110719'
UNION ALL SELECT '20110720'
UNION ALL SELECT '20110725'
UNION ALL SELECT '20110726'
UNION ALL SELECT '20110802'
UNION ALL SELECT '20110804'
UNION ALL SELECT '20110811'
UNION ALL SELECT '20090611'
UNION ALL SELECT '20091124'
UNION ALL SELECT '20100201'
UNION ALL SELECT '20100202'
UNION ALL SELECT '20100204'
UNION ALL SELECT '20100220'
UNION ALL SELECT '20100305'
UNION ALL SELECT '20100323'
UNION ALL SELECT '20100414'
UNION ALL SELECT '20100417'
UNION ALL SELECT '20100508'
UNION ALL SELECT '20100512'
UNION ALL SELECT '20100527'
UNION ALL SELECT '20100616'
UNION ALL SELECT '20100702'
UNION ALL SELECT '20100705'
UNION ALL SELECT '20100707'
UNION ALL SELECT '20100708'
UNION ALL SELECT '20100710'
UNION ALL SELECT '20100711'
UNION ALL SELECT '20100712'
UNION ALL SELECT '20100717'
UNION ALL SELECT '20100719'
UNION ALL SELECT '20100722'
UNION ALL SELECT '20100723'
UNION ALL SELECT '20100724'
UNION ALL SELECT '20100725'
UNION ALL SELECT '20100730'
UNION ALL SELECT '20100805'
UNION ALL SELECT '20100806'
UNION ALL SELECT '20100808'
UNION ALL SELECT '20100812'
UNION ALL SELECT '20100814'
UNION ALL SELECT '20100815'
UNION ALL SELECT '20100816'
UNION ALL SELECT '20100818'
UNION ALL SELECT '20100821'
UNION ALL SELECT '20100824'
UNION ALL SELECT '20100826'
UNION ALL SELECT '20100829'
UNION ALL SELECT '20100903'
UNION ALL SELECT '20100906'
UNION ALL SELECT '20100912'
UNION ALL SELECT '20100914'
UNION ALL SELECT '20100915'
UNION ALL SELECT '20100917'
UNION ALL SELECT '20100918'
UNION ALL SELECT '20100921'
UNION ALL SELECT '20100924'
UNION ALL SELECT '20100926'
UNION ALL SELECT '20100927'
UNION ALL SELECT '20100929'
UNION ALL SELECT '20100930'
UNION ALL SELECT '20101001'
UNION ALL SELECT '20101003'
UNION ALL SELECT '20101005'
UNION ALL SELECT '20101006'
UNION ALL SELECT '20101008'
UNION ALL SELECT '20101011'
UNION ALL SELECT '20101012'
UNION ALL SELECT '20101014'
UNION ALL SELECT '20101015'
UNION ALL SELECT '20101017'
UNION ALL SELECT '20101021'
UNION ALL SELECT '20101024'
UNION ALL SELECT '20101026'
UNION ALL SELECT '20101027'
UNION ALL SELECT '20101029'
UNION ALL SELECT '20101031'
UNION ALL SELECT '20101101'
UNION ALL SELECT '20101103'
UNION ALL SELECT '20101104'
UNION ALL SELECT '20101105'
UNION ALL SELECT '20101106'
UNION ALL SELECT '20101110'
UNION ALL SELECT '20101113'
UNION ALL SELECT '20101115'
UNION ALL SELECT '20101116'
UNION ALL SELECT '20101118'
UNION ALL SELECT '20101120'
UNION ALL SELECT '20101122'
UNION ALL SELECT '20101123'
UNION ALL SELECT '20101125'
UNION ALL SELECT '20101128'
UNION ALL SELECT '20101130'
UNION ALL SELECT '20101202'
UNION ALL SELECT '20101205'
UNION ALL SELECT '20101207'
UNION ALL SELECT '20101208'
UNION ALL SELECT '20101212'
UNION ALL SELECT '20101217'
UNION ALL SELECT '20101218'
UNION ALL SELECT '20101219'
UNION ALL SELECT '20101221'
UNION ALL SELECT '20101223'
UNION ALL SELECT '20101224'
UNION ALL SELECT '20101226'
UNION ALL SELECT '20101231'
UNION ALL SELECT '20110101'
UNION ALL SELECT '20110105'
UNION ALL SELECT '20110112'
UNION ALL SELECT '20110113'
UNION ALL SELECT '20110115'
UNION ALL SELECT '20110117'
UNION ALL SELECT '20110121'
UNION ALL SELECT '20110124'
UNION ALL SELECT '20110127'
UNION ALL SELECT '20110129'
UNION ALL SELECT '20110131'
UNION ALL SELECT '20110201'
UNION ALL SELECT '20110202'
UNION ALL SELECT '20110204'
UNION ALL SELECT '20110207'
UNION ALL SELECT '20110209'
UNION ALL SELECT '20110211'
UNION ALL SELECT '20110214'
UNION ALL SELECT '20110216'
UNION ALL SELECT '20110217'
UNION ALL SELECT '20110219'
UNION ALL SELECT '20110220'
UNION ALL SELECT '20110222'
UNION ALL SELECT '20110223'
UNION ALL SELECT '20110225'
UNION ALL SELECT '20110228'
UNION ALL SELECT '20110303'
UNION ALL SELECT '20110305'
UNION ALL SELECT '20110306'
UNION ALL SELECT '20110308'
UNION ALL SELECT '20110310'
UNION ALL SELECT '20110312'
UNION ALL SELECT '20110313'
UNION ALL SELECT '20110315'
UNION ALL SELECT '20110318'
UNION ALL SELECT '20110322'
UNION ALL SELECT '20110324'
UNION ALL SELECT '20110325'
UNION ALL SELECT '20110327'
UNION ALL SELECT '20110330'
UNION ALL SELECT '20110401'
UNION ALL SELECT '20110404'
UNION ALL SELECT '20110407'
UNION ALL SELECT '20110409'
UNION ALL SELECT '20110411'
UNION ALL SELECT '20110412'
UNION ALL SELECT '20110413'
UNION ALL SELECT '20110414'
UNION ALL SELECT '20110419'
UNION ALL SELECT '20110420'
UNION ALL SELECT '20110425'
UNION ALL SELECT '20110427'
UNION ALL SELECT '20110428'
UNION ALL SELECT '20110430'
UNION ALL SELECT '20110502'
UNION ALL SELECT '20110505'
UNION ALL SELECT '20110507'
UNION ALL SELECT '20110510'
UNION ALL SELECT '20110513'
UNION ALL SELECT '20110515'
UNION ALL SELECT '20110516'
UNION ALL SELECT '20110521'
UNION ALL SELECT '20110523'
UNION ALL SELECT '20110524'
UNION ALL SELECT '20110525'
UNION ALL SELECT '20110527'
UNION ALL SELECT '20110528'
UNION ALL SELECT '20110530'
UNION ALL SELECT '20110601'
UNION ALL SELECT '20110602'
UNION ALL SELECT '20110607'
UNION ALL SELECT '20110609'
UNION ALL SELECT '20110610'
UNION ALL SELECT '20110615'
UNION ALL SELECT '20110617'
UNION ALL SELECT '20110618'
UNION ALL SELECT '20110620'
UNION ALL SELECT '20110621'
UNION ALL SELECT '20110623'
UNION ALL SELECT '20110626'
UNION ALL SELECT '20110628'
UNION ALL SELECT '20110629'
UNION ALL SELECT '20110630'
UNION ALL SELECT '20110701'
UNION ALL SELECT '20110706'
UNION ALL SELECT '20110707'
UNION ALL SELECT '20110708'
UNION ALL SELECT '20110715'
UNION ALL SELECT '20110717'
UNION ALL SELECT '20110721'
UNION ALL SELECT '20110722'
UNION ALL SELECT '20110727'
UNION ALL SELECT '20110729'
UNION ALL SELECT '20110801'
UNION ALL SELECT '20110810'
SELECT
CAST(RD.CompletionDate AS datetime) AS casts_fine
FROm
@REAL_DATES RD
Ich schätze die Kommentare zu SSIS oder anderen Ansätzen, aber wir sind zu diesem Zeitpunkt im Spiel mit dem TSQL -Konvertierungsansatz verheiratet. Wenn jemand darauf hinweisen kann, was mir fehlt, werde ich mein erstes Kind nach Ihnen benennen, vorausgesetzt, es macht Ihnen nichts aus, Ihren Namen in James zu ändern.
Lösung
Was passiert, wenn Sie das tun?
DECLARE @REAL_DATES TABLE
(
CompletionDate VARCHAR(46)
);
INSERT INTO
@REAL_DATES
SELECT CompletionDate
FROM dbo.Entity;
SELECT
CAST(RD.CompletionDate AS datetime) AS casts_fine
FROM @REAL_DATES RD;
Was ich auf Twitter hatte, war, dass der Conversion vom Optimierer versucht werden kann Vor Zeilen werden beseitigt, sodass Sie nicht nur die CompletionDate -Werte berücksichtigen können, die vom Join zurückgegeben werden.
Mein erster Vorschlag wäre, den richtigen Datentyp zu verwenden. Warum verwenden Sie VARCHAR (46), um ein Datum zu speichern? Aus diesem Grund haben Sie schlechte Daten in der Tabelle und warum Sie explizit konvertieren müssen, wenn Sie reiche Daten möchten, die keine Zeichenfolge sind (und in erster Linie niemals eine Zeichenfolge gewesen sein sollte).
Mein nächster Vorschlag wäre, alle Daten in dieser Spalte zu korrigieren und Maßnahmen einzurichten, damit sie nicht wieder ungültig werden. Zum Beispiel eine Überprüfung, die validiert ISDATE(columnname) = 1.
Wenn Sie diese beiden fehlschlagen, ist es als nächstes, die Daten an den Client zurückzugeben und zu lassen es Konvertieren Sie in DateTime oder zur Anzeige oder was Sie haben. Egal wo Sie die Zeilen herausfiltern, die das Problem verursachen, der Optimierer könnte Drücken Sie diese Bewertung so, dass der Konvertit versucht wird, bevor die schlechten Reihen ausgeschlossen werden.
Und schließlich können Sie das Ergebnis der Abfrage in eine TEMP -Tabelle / Tabellenvariable ablegen und den Konvertit als zweiten Schritt bei der Abfrage dieses Zwischenobjekts ausführen (da Sie sicher sein sollten, dass die Daten hier gültig sind - können Sie tatsächlich überprüfen Erstens und erhöhen Sie einen Fehler, wenn Ihr Join einige Zeilen mit ungültigen Daten zurückgab.
Fazit: (a) Sie können keine Annahmen darüber treffen, wo im Stapel ein Konvertierungsversuch durchgeführt wird, und (b) diese Problemumgehungen und Hacks wären nicht erforderlich, wenn Sie den richtigen Datentyp verwenden.
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