要先把日期截出来再用CONVERT转换

SELECT CONVERT(DATE, LEFT(YourDateColumn, 8)) AS ConvertedDateFROM YourTableName

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或者拼接后转换

SELECT 

    CONVERT(DATETIME, 

        SUBSTRING('20230301150037', 1, 8) + '-' + 

        SUBSTRING('20230301150037', 9, 2) + '-' + 

        SUBSTRING('20230301150037' 11, 2) + ' ' + 

        SUBSTRING('20230301150037', 13, 2) + ':' + 

        SUBSTRING('20230301150037', 15, 2) + ':' + 

        SUBSTRING('20230301150037', 17, 2)

    ) AS ConvertedDateTime