Power Platform Community Forum Thread Details

Hello everyone,

I have been struggling with a Power Automate flow for days and I'm hoping someone can help me.

My setup:

Excel Online (Business) file stored on OneDrive.
Table name: Tabela1
Columns:
- ID (Key column, value: 001)
- Item (Text: Glicose)
- SaldoInicial (Number: 10)
- SaldoAtual (Number: 10, this is the column that needs to be updated)
- Retirada (Number: 0, this column updates correctly)

Microsoft Forms:

One question (choice): "Select item" (Glicose)
Second question (number): "Quantity withdrawn"

My Flow steps:

Trigger: When a new response is submitted (Microsoft Forms)
Get response details (Microsoft Forms)
Get a row (Excel Online Business) – Key column: ID, Key value: 001
Compose – Expression:
sub(int(coalesce(outputs('Obter_uma_linha')?['body/SaldoAtual'], '0')), int(coalesce(outputs('Obter_os_detalhes_da_resposta')?['answers']?[1]?['text'], '0')))
Initialize variable (NovoSaldo, Integer) – Value: Outputs from Compose
Update a row (Excel Online Business) – Key column: ID, Key value: 001
- Advanced parameters:
  - Retirada (mapped to "Quantity withdrawn" from Forms) → WORKS
  - SaldoAtual (mapped to variable NovoSaldo) → DOES NOT WORK

The problem:
The Retirada column updates correctly (e.g., if I withdraw 5, it shows 5).
The SaldoAtual column does not update at all (stays at the original value, e.g., 10).
The flow runs successfully with no errors.

I have already tried:

Using coalesce and int in the expression
Deleting and recreating the "Update a row" action
Renaming columns to simple names (no underscores, no spaces)
Converting the Excel range to a table (Insert > Table)

What I suspect:
The "Update a row" action is NOT writing to the SaldoAtual column, even though it is mapped correctly in the advanced parameters. The column name is exactly the same in Excel and in Power Automate.

Can someone please help me understand why Power Automate won't write to the SaldoAtual column?

Thank you very much!

Categories:

Power Automate Desktop

Hi there! 👋

I can see exactly what's happening here — this is a very common gotcha with the Excel Online (Business) "Update a row" action. Let me explain and give you the fix.

🔍 Root Cause: Variable Output vs. Dynamic Content Mapping

The issue is almost certainly how the NovoSaldo variable value is being passed to the Update a row action.

When you use Initialize variable and then map it in Update a row, you need to reference the variable using the expression variables('NovoSaldo') — not the raw Compose output. If you accidentally selected the Compose output directly into the SaldoAtual field (instead of the variable), the value may not be resolving correctly.

Per Use variables in Power Automate – Microsoft Learn:

"Variables must be set using Set variable before being referenced in subsequent actions. The value of the variable is the one set at the time of the action, not at the time of definition."

✅ Fixes to Try

1. Verify the expression in "Update a row" for SaldoAtual

In the Update a row action, the SaldoAtual field should contain this expression (added via the expression editor, not as plain text):

variables('NovoSaldo')

2. Confirm Compose output feeds the variable correctly

Your Initialize variable step's Value should be set to outputs('Compose') via the dynamic content picker — not hardcoded text. If it's pointing to the wrong output, NovoSaldo may be null or 0 when Update a row runs.

3. Column name exact match (case-sensitive)

The Excel Online (Business) connector is case-sensitive for column header names. In the Update a row Advanced parameters, confirm SaldoAtual exactly matches the Excel table column header — including capitalization. Per Excel Online (Business) connector – Microsoft Learn, the action maps fields by exact name.

4. Confirm the table key is unique

The action uses Key column: ID, Key value: 001 — make sure exactly one row in the table has ID = 001. If multiple rows match, the action may silently skip or produce unexpected behavior.

📋 References

Found this helpful? Please mark ✅ "Does this answer your question?" so others searching for the same issue can find it quickly. A 👍 on "Was this reply helpful?" or a ♥ Like is also much appreciated!

Raghav Mishra — LinkedIn | PowerAI Labs