带有“where”子句的 SQL 查询 XML答案

【问题标题】：SQL Query XML with 'where' clause带有“where”子句的 SQL 查询 XML
【发布时间】：2020-02-24 16:28:29
【问题描述】：

我正在尝试基于 XML 属性检索单行数据。

我目前的 SQL 是：

select C.query('.')
from Bookmarks
cross apply XMLValue.nodes('/rdBookmarks/Bookmark') as T(C)

本次查询返回的数据为（4行数据）

   <Bookmark Report="DataExplorer" Name="DataExplorer" CustomColumn1="Analysis" CustomColumn2="Data Explorer" Description="Benefit Plan Count" SaveTime="2020-02-21T10:44:36-05:00" BookmarkID="79638e95-c5b7-43f1-b180-f5f31b50dea4" ExtraFile="Bookmarks_79638e95-c5b7-43f1-b180-f5f31b50dea4.xml">
        <RequestParameters rdAgLoadSaved="Bookmarks_79638e95-c5b7-43f1-b180-f5f31b50dea4.xml" />
        <SessionParameters />
    </Bookmark>

    <Bookmark Report="People.ContactInfo.EmergencyContactList" Name="" CustomColumn1="Report" CustomColumn2="Emergency Contact List" Description="Engineering Emergency Contacts" SaveTime="2020-02-21T11:48:28-05:00" BookmarkID="953e67ef-d45e-4fac-8d71-b2153a726612" FolderID="9ef9c6db-73d7-439e-b465-cc3c45d37397">
         <RequestParameters inpMultiSelect_EmployeeStatus="" inpMultiSelect_Employer="" inpMultiSelect_OrgLevel1="22" inpMultiSelect_OrgLevel2="" inpMultiSelect_OrgLevel3="" inpMultiSelect_OrgLevel4="" inpMultiSelect_OrgLevel5="" inpMultiSelect_Manager="" inpMultiSelect_EmployeeType="" inpMultiSelect_SalariedHourly="" inpMultiSelect_ExemptStatus="" inpMultiSelect_JobTitle="" inpMultiSelect_State="" inpLastHireDate_Start="" inpLastHireDate_End="" inpEmpNo="" inpFirstName="" inpLastName="" inpCheckDate_Start="" inpCheckDate_End="" inpPeriodDate_Start="" inpPeriodDate_End="" inpMultiSelect_Category="" inpMultiSelect_EDTCode="" inpMultiSelect_Class1="" inpMultiSelect_Class2="" inpMultiSelect_Class3="" inpMultiSelect_Class4="" inpSelect_SelectionList="" inpMultiSelect_PostedStatus="" inpCheckBox_AllowBlankDates="" inpCheckBox_DefaultChecked_Manual="1" inpDate_SingleDate="" inpDate_Manual_SingleDate="" inpDateRange_Start="" inpDateRange_End="" inpDateRange2_Start="" inpDateRange2_End="" inpDateRange3_Start="" inpDateRange3_End="" inpDateRangeBlankDate_Start="" inpDateRangeBlankDate_End="" inpSelect_List="" inpMultiSelect_AnniversaryDateMonth="" inpMultiSelect_BenefitType="" inpMultiSelect_BenefitPlan="" inpMultiSelect_BirthDateMonth="" inpMultiSelect_BloodType="" inpMultiSelect_Event="" inpMultiSelect_EventLicenseCertif="" inpMultiSelect_NoteAuthor="" inpMultiSelect_NoteType="" inpMultiSelect_PastDue="" inpMultiSelect_PayFrequency="" inpMultiSelect_SalaryGrade="" inpMultiSelect_Skill="" inpMultiSelect_SourceData="" inpMultiSelect_SourceData2="" inpMultiSelect_UnionAffiliation="" inpMultiSelect_WaivedBenefit="" />
         <SessionParameters />
    </Bookmark>

    <Bookmark Report="TotalRewards.Compensation.SalaryAnalysis" Name="" CustomColumn1="Analysis" CustomColumn2="Salary Analysis" Description="Annual Pay by Employee" SaveTime="2020-02-21T12:03:02-05:00" BookmarkID="30da52af-55d3-4c06-985a-12d428731773" ExtraFile="Bookmarks_30da52af-55d3-4c06-985a-12d428731773.xml">
        <RequestParameters rdAgLoadSaved="Bookmarks_30da52af-55d3-4c06-985a-12d428731773.xml" />
        <SessionParameters />
    </Bookmark>

    <Bookmark Report="Payroll.PayrollProcessing.PayrollAnalysis" Name="" CustomColumn1="Report" CustomColumn2="Payroll Analysis" Description="Payroll Age 40-49" FolderID="9ef9c6db-73d7-439e-b465-cc3c45d37397" SaveTime="2020-02-21T12:50:26-05:00" BookmarkID="2f02d5ab-b15d-46f3-a669-04ab6fbfdfbe" ExtraFile="Bookmarks_2f02d5ab-b15d-46f3-a669-04ab6fbfdfbe.xml">
        <RequestParameters inpMultiSelect_EmployeeStatus="" inpMultiSelect_Employer="" inpMultiSelect_OrgLevel1="" inpMultiSelect_OrgLevel2="" inpMultiSelect_OrgLevel3="" inpMultiSelect_OrgLevel4="" inpMultiSelect_OrgLevel5="" inpMultiSelect_Manager="" inpMultiSelect_EmployeeType="" inpMultiSelect_SalariedHourly="" inpMultiSelect_ExemptStatus="" inpMultiSelect_JobTitle="" inpMultiSelect_State="" inpLastHireDate_Start="" inpLastHireDate_End="" inpEmpNo="" inpFirstName="" inpLastName="" inpCheckDate_Start="" inpCheckDate_End="" inpPeriodDate_Start="" inpPeriodDate_End="" inpMultiSelect_Category="" inpMultiSelect_EDTCode="" inpMultiSelect_Class1="" inpMultiSelect_Class2="" inpMultiSelect_Class3="" inpMultiSelect_Class4="" inpSelect_SelectionList="" inpMultiSelect_PostedStatus="" inpCheckBox_AllowBlankDates="" inpCheckBox_DefaultChecked_Manual="" inpDate_SingleDate="" inpDate_Manual_SingleDate="" inpDateRange_Start="" inpDateRange_End="" inpDateRange2_Start="" inpDateRange2_End="" inpDateRange3_Start="" inpDateRange3_End="" inpDateRangeBlankDate_Start="" inpDateRangeBlankDate_End="" inpSelect_List="" inpMultiSelect_AnniversaryDateMonth="" inpMultiSelect_BenefitType="" inpMultiSelect_BenefitPlan="" inpMultiSelect_BirthDateMonth="" inpMultiSelect_BloodType="" inpMultiSelect_Event="" inpMultiSelect_EventLicenseCertif="" inpMultiSelect_NoteAuthor="" inpMultiSelect_NoteType="" inpMultiSelect_PastDue="" inpMultiSelect_PayFrequency="" inpMultiSelect_SalaryGrade="" inpMultiSelect_Skill="" inpMultiSelect_SourceData="" inpMultiSelect_SourceData2="" inpMultiSelect_UnionAffiliation="" inpMultiSelect_WaivedBenefit="" rdAgLoadSaved="Bookmarks_2f02d5ab-b15d-46f3-a669-04ab6fbfdfbe.xml" />
        <SessionParameters />
    </Bookmark>

但这会返回每个 Bookmark 元素（总共 4 个）。我想添加一个 where 子句以仅返回一个基于 BookmarkID 的 Bookmark 节点，但似乎无法弄清楚如何执行此操作。有没有办法添加类似

where C.query('@BookmarkID') = '953e67ef-d45e-4fac-8d71-b2153a726612'

这样只返回一个书签节点？

【问题讨论】：

标签： sql-server xml tsql

【解决方案1】：

您可以使用value() 方法获取单个值：

SELECT C.query('.'), BookmarkID = c.value('@BookmarkID', 'VARCHAR(36)')
FROM Bookmarks
CROSS APPLY XMLValue.nodes('/rdBookmarks/Bookmark') as T(C)
WHERE c.value('@BookmarkID', 'VARCHAR(36)') = '953e67ef-d45e-4fac-8d71-b2153a726612'

也可以直接在nodes()方法中过滤：

SELECT C.query('.'), BookmarkID = c.value('@BookmarkID', 'VARCHAR(36)')
FROM Bookmarks
CROSS APPLY XMLValue.nodes('/rdBookmarks/Bookmark[@BookmarkID="953e67ef-d45e-4fac-8d71-b2153a726612"]') as T(C);

【讨论】：