Hi,
I would like to merge two data sets. Dataset A contains the values of the variable x. Among them are duplicates and missing values. Dataset B contains the variables x and y. In the dataset B the variables x are unique, i.e. no duplicates and missing values. The variable y does contain duplicates, i.e. some unique values of x correspond to the same y value. I have tried "merge m:1 using dataset B", but I ve received the errror message that "the variable x does not uniquely identify observations in the using data", which makes sense. Dropping the duplicates from dataset B is not an option. The task I would like to perform would be quite easy in excel with the vlookup function, however this is not possible due to a high number of observations. Do you have any suggestions?

Thank you very much
Best
Denis