如果parent_item_id不包含值，则尝试仅包含以下代码行。
<xsl:value-of select="$sepstart" /><xsl:value-of select="parent_item_id"/><xsl:value-of select="$sepend" />
就上下文而言-这是Magento 2的销售出口。
我尝试用if语句包装它，但是我不知道自己在做什么！
<xsl:if parent_item_id= ''">
...
</xsl:if>
如果有帮助，这是完整的代码。
<xsl:template match="/">
<xsl:text>"Merchant Identifier","Order Ref","Date","Product Search Code","Parent","Description","Customer Name","Customer Email"
</xsl:text> <!-- This is the header line of the CSV file. It gets output once only, the 
 characters represent a line break that gets output after the header line. -->
<xsl:for-each select="objects/object"> <!-- for-each means that the template will loop through the objects/object nodes in the XML processed. So for every object (order, invoice, ...) the code below will be applied. -->
<xsl:for-each select="items/item"> <!-- Loop through items ordered -->
<!-- This means, loop through all items of an object and output the following: -->
<xsl:value-of select="$sepstart" />fff<xsl:value-of select="$sepend" />
<xsl:value-of select="$sepstart" /><xsl:value-of select="../../increment_id"/><xsl:value-of select="$sepend" /> <!-- The $sepstart variable outputs " to start a new field in the CSV file. Then using xsl:value-of select="../../increment_id" the "increment_id" field is pulled from the object level. ../../ means to get data from the "parent" level (we are looping through items and not through objects (orders). The $sepend variable then outputs ", to denote the end of the field in the CSV file. -->
<xsl:value-of select="$sepstart" /><xsl:value-of select="../../created_at"/><xsl:value-of select="$sepend" /><!-- Order date -->
<xsl:value-of select="$sepstart" /><xsl:value-of select="product_attributes/sku"/><xsl:value-of select="$sepend" /> <!-- Get the "sku" field -->
<xsl:value-of select="$sepstart" /><xsl:value-of select="parent_item_id"/><xsl:value-of select="$sepend" /> <!-- Get the "sku" field -->
<xsl:value-of select="$sepstart" /><xsl:value-of select="name"/><xsl:value-of select="$sepend" /> <!-- Get the "sku" field on item level -->
<xsl:value-of select="$sepstart" /><xsl:value-of select="../../shipping/prefix"/><xsl:text> </xsl:text><xsl:value-of select="../../shipping/firstname"/><xsl:text> </xsl:text><xsl:value-of select="../../shipping/lastname"/><xsl:value-of select="$sepend" /><!-- Name (prefix, forename, surname) -->
<xsl:value-of select="$sepstart" /><xsl:value-of select="../../customer_email"/><xsl:value-of select="$sepend" /><!-- customer email -->
<xsl:text>
</xsl:text>
</xsl:for-each> <!-- End item foreach -->
</xsl:for-each> <!-- End object foreach -->
</xsl:template>
</xsl:stylesheet>
</file>
</files>