PowerApps中如何评估空TextBox？Excel数据源查询异常求助

Let's break down why your original query isn't returning records, and how to fix the revised version you're trying to use.

1. The Root Cause of Your Original Empty Collection #

Your initial code uses Column2= " " to match empty values, but this is looking for cells that contain exactly one space character. Since your Excel Column2 has truly empty cells (not spaces), there's no match—hence the empty collection.

2. Key Issues with Your Revised Code #

Your proposed code ClearCollect(Test,LookUp(Table1,Column1=DataCardValue6.Text && Column2= IsBlank(Trim(Column2Name)))) has two critical problems:

• Typos in column name: You wrote Column2Name instead of your actual column name (should be Column2, matching your Excel table structure).
• Incorrect syntax for the blank check: The expression Column2= IsBlank(Trim(Column2)) doesn't make logical sense—you're comparing the column value to a boolean result (IsBlank() returns true/false), which will never be equal.

3. Correct Approach to Match Empty Column2 Values #

Excel handles empty cells differently than Power Apps at times: empty cells might come through as Blank() or an empty string "". To cover all edge cases (including accidental spaces), use this refined logic:

Option 1: Get a single matching record (using LookUp) #

If you only need the first record that meets your criteria:

ClearCollect(
    Test,
    LookUp(
        Table1,
        Trim(Column1) = Trim(DataCardValue6.Text) && 
        IsBlank(Trim(Column2))
    )
)

• Trim(Column1) ensures we ignore any leading/trailing spaces in both the Excel value and the input text, avoiding mismatches from accidental whitespace.
• IsBlank(Trim(Column2)) covers three scenarios:
  • Truly blank Excel cells
  • Cells stored as empty strings ""
  • Cells containing only spaces

Option 2: Get all matching records (using Filter) #

If you need every record that fits the criteria (not just the first), replace LookUp with Filter—this is a common oversight, since LookUp only returns one record:

ClearCollect(
    Test,
    Filter(
        Table1,
        Trim(Column1) = Trim(DataCardValue6.Text) && 
        IsBlank(Trim(Column2))
    )
)

4. Additional Checks to Rule Out Other Issues #

• Refresh your Excel connection: Sometimes changes in your Excel table don't sync automatically to Power Apps—use the "Refresh" option on your data source to ensure you're working with the latest data.
• Fix the Column2 Default property: You set Column2's Default to a space (" "). If users save records with this value, those cells will have a space instead of being blank. Change the Default to Blank() if you want to store true empty values.
• Test the condition individually: Put IsBlank(Trim(Column2)) in a label's Text property (binding it to a Gallery item) to confirm it correctly identifies empty Column2 cells in your data.

内容的提问来源于stack exchange，提问作者biggboss2019