I would like to add to my database new columns with external information, including solubility calculated by another software. However the file with those values has .txt extension (attachment). How can I upload the values to the database ?
Importing text files with merging data is supported feature. In your case it looks like tab separated file (tab character is used for separation values).
The problem is that your file is not in correct format, but looks partly like html. You can see it if you open the file in Windows Notepad for example. The file begins with:
These lines must be deleted before importing the file. The file should begin with column names as first line. The same problem is in the end of file. It's better to delete also these last two lines. I corrected the example file (see attachment) so you can compare it with original.
Once you have you file in valid txt format you can import it into existing entity so new columns will be added to existing table. Please follow these instructions.