Updating Field Values During Data Entity Import in Dynamics 365 Finance & Operations

In Dynamics 365 Finance & Operations (D365FO), there are scenarios where data needs to be enriched or recalculated during data import. This can be achieved by overriding the mapEntityToDataSource() method in the Data Entity.

This blog explains a real-world example where the Vendor Name is populated automatically while importing vendor invoice data through a data entity.

Business Requirement

• Vendor invoice data is received from an external system
• Only the Vendor Tax ID is provided in the import file
• Vendor Name should be derived automatically during the import

Technical Approach

We override the mapEntityToDataSource() method and update the target datasource buffer before the record is written to the database.

X++ Code Implementation

public void mapEntityToDataSource(
    DataEntityRuntimeContext _entityCtx,
    DataEntityDataSourceRuntimeContext _dataSourceCtx)
{
    super(_entityCtx, _dataSourceCtx);

    if (_dataSourceCtx.name() ==
        dataEntityDataSourceStr(TESTEdicomIncomingDocument, TESTVendInvoiceProcess))
    {
        TESTVendInvoiceProcess  TESTVendInvoiceProcess = _dataSourceCtx.getBuffer();
        LTMVendTable           ltmVendTable;
        VendTable              vendTable;
        DirPartyTable          dirParty;

        select firstOnly ltmVendTable
            where ltmVendTable.CountryDocNum == this.TaxId
            join firstOnly vendTable
                where vendTable.AccountNum == ltmVendTable.AccountNum;

        select firstOnly dirParty
            where dirParty.RecId == vendTable.Party;

        TESTVendInvoiceProcess.VendorName = dirParty.Name;
    }
}

When to Use mapEntityToDataSource()

• Derive values during import
• Apply default values
• Validate or adjust incoming data
• Populate fields not provided by the source system

Conclusion

The mapEntityToDataSource() method is a powerful extension point in D365FO data entities. Using it correctly helps ensure clean, consistent, and business-ready data during imports.

This pattern is especially useful in integration scenarios where source systems provide minimal data and enrichment is required on the D365FO side.