Issue fix with PostGreSQL tables data mapping

Problem Statement I have two tables in PostgreSQL database (Lead and Location table without any primary key). Lead table has information related to leads and extra two columns that is Latitude and Longitude(which is having a blank value). Location table has information related to address including latitude and longitude value for that pin code. Problem 1: I want to merge Latitude and Longitude value of Location table into the Lead table latitude and longitude column based on Pincode (matching value.) I have tried JOIN on both tables, but result value is repeating.I want only one value (Latitude and Longitude from Location table) for matching pin code(which is first found in Location table). Problem 2: In Geoda when I am trying to merge Lead and Location table based key (Pin code)(Merge by key values) option following error will occur Your table cannot be merged because the key field “Pin Code” is not [login to view URL] contains undefined or duplicate values.