When building apps using Microsoft Power Apps integrated with Microsoft Dynamics 365 Finance and Operations, a common requirement is to display:
- Item Name / Description on purchase lines
- Vendor Name on purchase order header
However, many developers quickly realize that:
These fields are not directly available on tables or exposed in standard data entities.
The Challenge
In Dynamics 365 F&O:
- Purchase line entities expose ItemId, but not the Item Name
- Purchase order header exposes Vendor Account, but not the Vendor Name
This becomes a limitation when building Power Apps, where you need user-friendly information instead of IDs.
The Right Approach: Use Computed Columns
To solve this, the recommended approach is to create computed fields (computed columns) in the data entity.
Instead of:
- Writing X++ logic using virtual fields
- Populating values in postLoad() (which impacts performance)
You should:
- Create a computed column
- Let SQL Server calculate the value
- Expose it directly to Power Apps via the data entity
Why Computed Columns Work Best for Power Apps
Computed columns:
- Are calculated at the database (SQL) level
- Provide better performance
- Support filtering and searching
- Are ideal for read scenarios like Power Apps
This makes them perfect for displaying:
- Vendor Name
- Item Name
Implementation Overview
- Extend the Data Entity
Use either:
- A standard data entity extension, or
- A custom data entity
2. Create a Computed Method
Create a static method that returns a SQL expression to
fetch:
- Vendor Name from Vendor table
- Item Name from Item table
3. Add Unmapped Field
In the data entity:
- Create
a new unmapped string field - Set:
- IsComputedField = Yes
- Reference your computed method
4. Extend Staging Table
Add the same field in the staging table with:
- Matching name
- Appropriate string size or EDT
Below is the sample code for Vendor name
public static server str getVendorName()
{
var orderAccount = SysComputedColumn::returnField(
tableStr(PurchApprovalHeaderEntity),
identifierstr(PurchTable),
fieldStr(PurchTable, OrderAccount)
);
// Correct vendor name lookup via DirPartyTable
return strFmt(“(SELECT TOP 1 P.Name ” +
” FROM VendTable V ” +
” JOIN DirPartyTable P ON V.Party = P.RecId ” +
” WHERE V.AccountNum = %1)”, OrderAccount);
}
Below is the sample code for Item name/description
public static server str getItemDescription()
{
// ItemId from the line (outer row)
str itemIdField = SysComputedColumn::returnField(
tableStr(PurchApprovalAttachedLineEntity),
identifierStr(PurchLine),
fieldStr(PurchLine, ItemId));
// Company filter omitted because PurchLine has no DataAreaId in your env.
// This relies on ItemId uniqueness or returns the first match.
return strFmt(
“COALESCE((” +
” SELECT TOP 1 I.NameAlias ” +
” FROM InventTable I WITH (READUNCOMMITTED) ” +
” WHERE I.ItemId = %1″ +
“), ”)”,
itemIdField);
}
Example Use Cases in Power Apps
Once the computed fields are added:
Purchase Order App
- Display:
- Vendor Account → Vendor Name
- Improves usability for business users
Purchase Line App
- Display:
- ItemId → Item Name
- Avoids confusion with technical IDs
Key Takeaway
If you’re building apps in Microsoft Power Apps on top of Microsoft Dynamics 365 Finance and Operations:
- Item Name and Vendor Name are not directly available fields
- Do not rely on virtual fields or postLoad() logic
- Use computed columns in data entities for a clean and high-performance solution
Conclusion
Computed columns provide a simple, scalable, and high-performance way to enrich your data entities for Power Apps.
By exposing Item Name and Vendor Name through computed fields, you ensure:
- Better user experience
- Faster data retrieval
- Cleaner architecture
