It looks like you dropped the word "FROM" within the SELECT statement.
The word HAVE (or HAVING) is supposed to represent the name of your data set. Most solutions that are posted here will use WANT as the name of the data set you want to obtain, and HAVE as the name of the data set you are starting with. So just replace that with the name of your data set.
Learn the difference between classical and Bayesian statistical approaches and see a few PROC examples to perform Bayesian analysis in this video.
Find more tutorials on the SAS Users YouTube channel.