title: Postgres Query: finding values that are not numbers
body: <p>I have been importing data from a Pandas Dataframe to a postgres DB using my own custom import script. Unfortunately, my data is not tidy which caused every single one of my columns to be parsed as a text. Is there any way where I could get the entries where a certain column value is NOT a number? My plan is to delete those records and convert the column to a numeric type</p>
  
  <p>Thanks!</p>