XSLT Multiple Child - xslt

Question

I have an XML which has multiple child elements. Item Group will be only once and can have minimum or more Transactions for each Item_Entry. In other words, Item_Entry will have only one Item_Group, but can have one more more Transactions. I need to generate my output based on the transaction. My output should contain all the transactions for each item. I need some help with XSLT for this.
XML:
<?xml version='1.0' encoding='UTF-8'?>
<Item_Data>
<Item_Entry>
<Item_group>
<Item_Name>Name1</Item_Name>
<Item_ID>0001</Item_ID>
<Sale_Date>2019-01-01-00:00</Sale_Date>
</Item_group>
<Transaction>
<TxnCode Description="Store1">
<Store type="StoreNum">1001</Store>
</TxnCode>
<SalesTime>2019-01-01-07:00</SalesTime>
<SaleAmount>10</SaleAmount>
</Transaction>
<Transaction>
<TxnCode Description="Store2">
<Store type="StoreNum">1002</Store>
</TxnCode>
<SalesTime>2019-01-01-08:00</SalesTime>
<SaleAmount>11</SaleAmount>
</Transaction>
</Item_Entry>
<Item_Entry>
<Item_group>
<Item_Name>Name2</Item_Name>
<Item_ID>0002</Item_ID>
<Sale_Date>2019-01-02-00:00</Sale_Date>
</Item_group>
<Transaction>
<TxnCode Description="Store3">
<Store type="StoreNum">1003</Store>
</TxnCode>
<SalesTime>2019-01-02-09:00</SalesTime>
<SaleAmount>12</SaleAmount>
</Transaction>
<Transaction>
<TxnCode Description="Store4">
<Store type="StoreNum">1004</Store>
</TxnCode>
<SalesTime>2019-01-02-10:00</SalesTime>
<SaleAmount>13</SaleAmount>
</Transaction>
</Item_Entry>
</Item_Data>
Output:
Item_ID,Item_Name,Sale_Date,Store_Name,Store_Num,Sales_Time,Sale_Amount
0001,Name1,2019-01-01,Store1,1001,2019-01-01-07:00,10
0001,Name1,2019-01-01,Store2,1002,2019-01-01-08:00,11
0002,Name2,2019-01-02,Store3,1003,2019-01-01-09:00,12
0002,Name2,2019-01-02,Store4,1004,2019-01-01-10:00,13
Thanks,
Ug

Answer 1

For XML to CSV or one "record" per line transformation I think (at least in XSLT 2/3) it is easy to push the relevant element representing a "record" or line to a template (i.e. in your case <xsl:apply-templates select="//Transaction"/>) and then in there to collect all data you want to output in the select of an xsl:value-of with the right separator e.g.
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
exclude-result-prefixes="#all"
version="3.0">
<xsl:output method="text"/>
<xsl:template match="/">
<xsl:text>Item_ID,Item_Name,Sale_Date,Store_Name,Store_Num,Sales_Time,Sale_Amount
</xsl:text>
<xsl:apply-templates select="//Transaction"/>
</xsl:template>
<xsl:template match="Transaction">
<xsl:value-of select="../Item_group!(Item_ID, Item_Name, substring(Sale_Date, 1, 10)), */#* | .//*[not(*)]" separator=","/>
<xsl:text>
</xsl:text>
</xsl:template>
</xsl:stylesheet>
https://xsltfiddle.liberty-development.net/jz1PuNX