I hope somebody can help me, because it is very imoptant for me!

Without seeing your database structure, I cannot speak very specifically, but what I would do would be to either split out the questions from their data (so one table would contain a list of all of the questions and then they would link either to the image table or the text table) or I would include both columns in the one table (text and image). If I did the second, it would be simpler but it would leave a lot of null columns (which can be ok).

In the second scenario, you would simply pick a random row, then test the text area to see if it is null (or the picture field). If it is null, choose the other one to display. If it isn't, display that field.

In the first example, you would need to do a second lookup based upon the specified type (a column saying text or image) into the second table (either the text table or the image table).

Hi.

So, according to your question there is some unclear moment.
Why do you need one column, which can contains differ data types ?)
Maybe it would be more resonable to create table with 2 columns(for appropriate data types text/image) which can contains NULL. In future when you try to populate test data, you goes through records and check for null some of column, and depend from return type null or smth else you create appropriate representation for that.

But also, i think it's possible to implement one column DB design.
Let assume, that you will create column whith BLOB data type and call it Data. Then you just populate data for test whith binary data representation.
For data retrieving, you will need to implemet validation stage and by that result populate your UI.