> For the complete documentation index, see [llms.txt](https://doc.wearepatchworks.com/product-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.wearepatchworks.com/product-documentation/blueprints/patchworks-blueprints/shopify-and-virtualstock-supplier/installation-guide-shopify-and-virtualstock-supplier/stage-4-update-cross-reference-lookups-shopify-to-virtualstock-supplier.md).

# Stage 4: Update cross-reference lookups (Shopify to Virtualstock Supplier)

## Introduction

Cross-reference lookup tables are used to convert given *Shopify* values to *Virtualstock Supplier* values. Conversion values are defined here and then called in process flow runs via [cross reference lookup transformations](/product-documentation/process-flows/cross-reference-lookups/using-a-cross-reference-lookup-in-field-transformations.md) applied to field mappings.

The following cross-reference lookup tables are installed as part of the *Shopify & Virtualstock Supplier* blueprint:

<table><thead><tr><th width="248">Cross-reference lookup</th><th>Notes</th></tr></thead><tbody><tr><td>SKU Lookup</td><td><p>Convert <em>Virtualstock Supplier</em> part numbers to <em>Shopify</em> SKUs (and vice versa).</p><p><br>In Shopify, the <code>variantId</code> is used when creating a sales order.  Patchworks makes a GraphQL call into Shopify to search for <code>variantId</code> based on the <code>SKU</code>, therefore the <code>SKU</code> must be unique. </p></td></tr><tr><td>Carrier Mapping</td><td>Convert your <em>Shopify</em> <code>tracking_company</code> values to <em>Virtualstock Supplier</em> <code>carrier</code> values. </td></tr></tbody></table>

You need to update these with your required values. You can add just a few that you know will cover testing requirements and come back to complete these tables later, or you can add everything now - it's up to you.

{% hint style="info" %}
The steps below show how to update cross-reference lookup tables manually however, you can also [import values](/product-documentation/process-flows/cross-reference-lookups/importing-and-exporting-cross-reference-lookups.md) (recommended for larger updates).
{% endhint %}

{% hint style="info" %}
For more information about cross-reference lookups, please see our [cross-reference lookups](/product-documentation/process-flows/cross-reference-lookups.md) pages.
{% endhint %}

## The steps

**Step 1**\
Select *process flows* > *cross-reference lookups* from the left-hand navigation menu (or click [here](https://app.wearepatchworks.com/cross-reference-lookups)). You will see two installed cross-reference tables: *Carrier Mapping* and *SKU Lookup*. For example:

<figure><img src="/files/P5zCwru6asiQGuLuU6NE" alt=""><figcaption></figcaption></figure>

**Step 2**\
Click the *Carrier Mapping* entry to view existing entries for converting *Shopify* carrier values (on the left) to *Virtualstock Supplier* carrier values (on the right):

<figure><img src="/files/SWNSFraG92ff5aPbbbJl" alt=""><figcaption></figcaption></figure>

**Step 3**\
[Add/update/remove existing](/product-documentation/process-flows/cross-reference-lookups/adding-a-cross-reference-lookup.md) entries as appropriate (placeholder values can be edited or removed).

{% hint style="info" %}
Your *Virtualstock Supplie*r merchant (e.g. John Lewis) should provide your required values.
{% endhint %}

{% hint style="info" %}
When we apply this table to a cross-reference lookup field transformation, we can choose whether the conversion is left-to-right or right-to-left.&#x20;
{% endhint %}

**Step 4**\
Check the [default value](/product-documentation/process-flows/cross-reference-lookups/adding-a-cross-reference-lookup.md) and change it as appropriate (leave blank for no default). If you change the default value, click the *update* button to confirm.

**Step 5**\
Save changes.

**Step 6**\
Navigate back to the *Cross-Reference lookups* page and click the *SKU Lookup* entry to view existing entries for converting *Virtualstock Supplier* part numbers (on the left) to Shopify SKUs (on the right), and versa:

<figure><img src="/files/csyBeFvjuuMnQzPf1XDs" alt=""><figcaption></figcaption></figure>

{% hint style="info" %}
When we apply this table to a cross-reference lookup field transformation, we can choose whether the conversion is left-to-right or right-to-left.&#x20;
{% endhint %}

**Step 7**\
[Add/update/remove existing](/product-documentation/process-flows/cross-reference-lookups/adding-a-cross-reference-lookup.md) entries as appropriate (placeholder values can be edited or removed).

**Step 8**\
Ensure that the *default value* is set to `n/a`. This is important as a subsequent filter will check for this.

**Step 9**\
Save changes.

**Step 10**\
Go to the [next stage](/product-documentation/blueprints/patchworks-blueprints/shopify-and-virtualstock-supplier/installation-guide-shopify-and-virtualstock-supplier/stage-5-review-and-test-the-orders-process-flow-shopify-and-virtualstock-supplier.md).