在 SQL 中正确过滤日期答案

【问题标题】：properly filtering Dates in SQL在 SQL 中正确过滤日期
【发布时间】：2020-01-28 19:23:10
【问题描述】：

我正在尝试执行我的查询，但只提取 2020 年的日期，当我添加 DatePart（2020 年）时，我没有得到任何结果，尽管有 2020 年的结果。系统数据的格式为 YEAR-MONTH-DAY HR:MIN:SEC:SEC。谁能指导我哪里出错了？

SELECT   CV3ClientVisit.ClientDisplayName, CV3ClientVisit.CurrentLocation, CV3ClientVisit.IDCode, CV3ClientVisit.VisitStatus, CV3Order.Name, CV3ClientVisit.TypeCode, 
                     CV3User.DisplayName AS [Performed By], CV3OrderTaskOccurrence.PerformedFromDtm AS [Performed When], CV3OrderTaskOccurrence.TouchedBy AS [Cosigned By], 
                     CV3OrderTaskOccurrence.TouchedWhen AS [Cosigned When]
FROM         CV3Client INNER JOIN
                     CV3TaskSignature ON CV3Client.GUID = CV3TaskSignature.ClientGUID INNER JOIN
                     CV3ClientVisit INNER JOIN
                     CV3Order ON CV3ClientVisit.GUID = CV3Order.ClientVisitGUID INNER JOIN
                     CV3OrderTaskOccurrence ON CV3Order.GUID = CV3OrderTaskOccurrence.OrderGUID INNER JOIN
                     CV3TaskStatusHistory ON CV3OrderTaskOccurrence.GUID = CV3TaskStatusHistory.OrderTaskOccurrenceGUID ON CV3Client.GUID = CV3Order.ClientGUID INNER JOIN
                     CV3User ON CV3OrderTaskOccurrence.PerformedProviderGUID = CV3User.GUID
WHERE     (CV3ClientVisit.TypeCode = 'Inpatient Admit') AND (CV3Order.Name = 'insulin lispro sliding scale injectable') AND (CV3ClientVisit.VisitStatus = 'ADM') AND 
                     (CV3OrderTaskOccurrence.TouchedWhen = DATEPART(YEAR, 2020))

【问题讨论】：

标签： sql filter datepart

【解决方案1】：

如果touchedwhen 是日期/时间，则使用如下内容：

(CV3OrderTaskOccurrence.TouchedWhen >= '2020-01-01' and
 CV3OrderTaskOccurrence.TouchedWhen < '2021-01-01' 
)

实际上，如果将值存储为字符串，这也可以，但我强烈建议您使用正确的数据类型存储值。

【讨论】：