when we lacked of some colums in validation set, how to use validation set in regression problem?

Question

I am doing the project related with regression problem like failure rate prediction.

For training data set, I have columns like below

I have 10 columns training data.

And for validation set, it is like below

It only has 3 columns. But in my knowlege, we have to have same columns for validation set as training set.

Is there any method to compare between target of training set and of validation set ?

I tried to do this using merge on multiple columns (like col A and col B). Like this, I think we can compare the target columns of each dataset.

Is it correct method ?

Thanks