When you add or regenerate a table you may see the warning:
Column '<column name>' of sheet '<sheet name>' contains mismatched formulas.
This article explains what this message means, how to find the mismatched formulas, and how to fix the mismatched formulas.
Understand mismatched formulas
When you add or regenerate a table, AppSheet checks the spreadsheet formulas in each column of your sheets. If a column contains a consistent spreadsheet formula, AppSheet recognizes the formula and stores it in the Spreadsheet formula property of that field.
To view the Spreadsheet formula property:
- Open your app in the editor.
- Go to the Data > Columns tab.
- Expand the table.
- Click the Edit (pencil) icon associated with the column.
- Expand Auto Compute.
- Check the Spreadsheet formula property.
When a field contains a Spreadsheet formula, AppSheet inserts that formula in that field for every newly added row.
Check spreadsheet formulas
AppSheet checks the sheet formula in every cell of a column. It does this by translating the sheet formula from the customary A1 format to R1C1 format. A1 format is the default sheet formula format used by both Google Sheets and Excel. R1C1 format is used less frequently, but it it is very useful when comparing one sheet formula to another. It is the easiest way to determine if two sheet formulas are exactly equivalent.
AppSheet computes the percentage of cells in the column that contain each type of R1C1 formula. AppSheet treats an empty cell with no formula as yet another type of formula (the "Empty Formula"). Every cell in the column contributes to the percentage of one type of formula or another.
If one type of R1C1 formula appears in a high percentage of column cells, AppSheet assigns that formula to the entire column. This approach allows AppSheet to detect the formula that appears most frequently while ignoring the occasional distinct formula type that might appear somewhere in the column.
Mismatched formulas
If a column contains mismatched formula, AppSheet reports the warning Column '<column name>' of sheet '<sheet name>' contains mismatched formulas. The warning goes on to report what mismatched formulas it has found and what rows contain each version of the mismatched formula. This can help you find the mismatched formulas. Often only one or two cells contain mismatched formulas.
You can resolve the mismatch by making the formulas in those cells consistent and regenerating the table. Every time you regenerate your table, AppSheet reexamines the formulas in each column of the table.
Find mismatched formulas
When the AppSheet app editor detects formula mismatches it displays a warning message containing:
- The number of mismatches found.
- The first five mismatched formulas in both A1 and R1C1 format along with the row numbers containing those formulas.
Use the warning information to find the mismatched formulas.
- Compare the formulas in R1C1 format. Matching formulas will have exactly the same formula value in R1C1 format. Mismatched formulas will have different formula values in R1C1 format. Even a single character difference in the R1C1 formats will result in a mismatch.
- Use the row numbers to find the rows having the mismatched formulas.
Fix mismatched formulas
One common cause of mismatching formulas is using a constant row number without specifying the row number in Absolute form. For example, a mismatched formula warning will occur if the formula $A10 appears in A1 format in every cell of a column. $A makes the column reference Absolute; however, the row number 10 is Relative because it is not preceded by a $. It will results in a different R1C1 formula value in each row of the sheet. If you intend to specify a constant row number, specify the A1 formula $A$10. In this A1 formula both the column and row are in Absolute form.