Question

在以下代码中声明;

declare namespace pd="http://cargowise.com/ediEnterprise/2011/10/11/systemUsage.xsd

重复6次，使代码变得非常混乱，更难以遵循：

SELECT XW_PK, xw_ExeVersion, xw_enterpriseCode, xw_DatabaseCode, xw_CompanyCode,
    Poodle.Love.value('declare namespace pd="http://cargowise.com/ediEnterprise/2011/10/11/systemUsage.xsd";
    (pd:action/@name)[1]', 'varchar(100)') Name,
    Poodle.Love.value('declare namespace pd="http://cargowise.com/ediEnterprise/2011/10/11/systemUsage.xsd";
    (pd:action/@started)[1]', 'varchar(100)') [Started],
    Poodle.Love.value('declare namespace pd="http://cargowise.com/ediEnterprise/2011/10/11/systemUsage.xsd";
    (pd:action/@ended)[1]', 'varchar(100)') [Ended],
    Poodle.Love.value('declare namespace pd="http://cargowise.com/ediEnterprise/2011/10/11/systemUsage.xsd";
    (pd:action/@Elapsed)[1]', 'varchar(100)') Elapsed,
    Poodle.Love.value('declare namespace pd="http://cargowise.com/ediEnterprise/2011/10/11/systemUsage.xsd";
    (pd:action/@elapsedWithChildren)[1]', 'varchar(100)') elapsedWithChildren
    FROM   stmusage
        CROSS APPLY xw_rawData.nodes('declare namespace pd="http://cargowise.com/ediEnterprise/2011/10/11/systemUsage.xsd";
        /pd:performanceMeasurement/pd:action') as Poodle(Love)

我想要做的只是声明命名空间一次并完成它。问题是每个xqueries都嵌入了一个字符串中 - 我并不完全确定 - 但是这些年来我所接受的经验给了我压倒性的印象，即这些字符串不会与每个字符串交互其他任何时候都很快。

Answer 1

我不知道您正在编写的编程语言，但在任何其他语言中，我会编写一个函数，将字符串“name”或“started”作为参数PPPPP并生成

Poodle.Love.value（'declare namespace d =“http://cargowise.com/ediEnterprise/2011/10/11/systemUsage.xsd”; （pd：action / @ {PPPPP}）[1]'，'varchar（100）'）

结果。

Answer 2

SELECT 
            XMLTable.actions.value('(@name)', 'varchar(100)') Name,
            XMLTable.actions.value('(@started)', 'datetime') [Started],
            XMLTable.actions.value('(@started)', 'datetime') + 
            convert(float, replace (replace (XMLTable.actions.value('(@elapsedWithChildren)', 'varchar(100)'),'PT',''),'S','')) / (60 * 60 * 24) Ended, --dodgy floating point rounding errors
            convert(float, replace (replace (XMLTable.actions.value('(@elapsed)', 'varchar(100)'),'PT',''),'S','')) Elapsed,
            convert(float, replace (replace (XMLTable.actions.value('(@elapsedWithChildren)', 'varchar(100)'),'PT',''),'S','')) ElapsedWithChildren,
            XMLTable.actions.value('@moduleId','varchar(100)') moduleid,
            XMLTable.actions.value('@actionCount','int') actionCount,
            XW_PK, XW_ExeVersion, XW_EnterpriseCode, XW_DatabaseCode, XW_CompanyCode, ExportType
            FROM StmUsage
                CROSS APPLY xw_rawData.nodes('declare namespace pd="http://cargowise.com/ediEnterprise/2011/10/11/systemUsage.xsd";
                /pd:performanceMeasurement/pd:action') XMLTable(actions)
            cross join (select 'Elapsed' ExportType union select 'ElapsedWithChildren') ExportTypeAlias

轻松！

删除重复且真正冗余的命名空间

2 个答案: