You can control column structure by changing your spreadsheet.
- Use the first worksheet. By default, AppSheet only uses the first worksheet of your spreadsheet file. And it only extracts one structured 'table' of data from that spreadsheet. So it is important that you put the appropriate data in the first worksheet. Note that AppSheet apps can utilize multiple spreadsheet files. Also as described in that section, you can explicitly specify a worksheet other than the first worksheet, if necessary.
- Just header + data please. You could put almost any content in a spreadsheet, including charts, pictures, free form text, etc. However, if the data isn't obviously tabular, AppSheet will probably fail to extract a tabular column structure. Ideally make the first row contain column headers and the rest of the rows contain data.
- Provide data for column type deduction. If possible, provide at least 5-10 rows of actual data in the spreadsheet. This allows AppSheet to look at the data and deduce their types. For example, if every row of a column has an entry that looks like 'something.jpg', AppSheet will recognize this as an Image. However, users sometimes start with a blank spreadsheet and that leads AppSheet to make poor guesses.
- Use data formats consistently, as described in the article outlining the effective use of column headers.
- Use spreadsheet data validation rules where appropriate, as described in the article about dropdowns from worksheet validation rules.
- Provide data for key identification, as described inthe article about dropdowns from worksheet validation rules.
- If AppSheet still doesn't quite get the column structure right, you can tweak it in the Editor.