How do I create a dropdown field using a specific column as my data source?

[Excelsoxls]

I've tried using a ref column but that only asks me what table I'd like to use, and I want values from a specific column of that table to be shown on my dropdown field.

[Suvrutt_Gurjar · Accepted solution]

Drop-down from Valid_If - AppSheet Help

[JPAlpano]

Correct. And you ise a SELECT() in the valid-if expression. 

[Excelsoxls]

In my case I just needed to name the table[column] in the formula. Used a sort function as well just for convenience.

[JPAlpano]

Oh, right! I almost forgot about that shorthand - which is also what works for cascaded-dropdowns (dependent dropdowns).