title: how to add a Incremental column ID for a table in spark SQL
body: <p>I'm working on a spark mllib algorithm. The dataset I have is in this form </p>
  
  <p>Company":"XXXX","CurrentTitle":"XYZ","Edu_Title":"ABC","Exp_mnth":.(there are more values similar to these)</p>
  
  <p>Im trying to raw code String values to Numeric values. So, I tried using zipwithuniqueID for unique value for each of the string values.For some reason I'm not able to save the modified dataset to the disk. Can I do this in any way using spark SQL? or what would be the better approach for this?</p>