title: MySQL LOAD DATA IN FILE update a single column
body: <p>I am trying to populate a sparse table, from a set of 10 input tsv files.</p>
  
  <p>Each file has primary_key, column values for one of the columns on the destination table.</p>
  
  <p>However each file has a different set of primary keys for which it has values.</p>
  
  <p>I wish to load these into the table using LOAD DATA IN FILE.</p>
  
  <p>The first file loads fine, but the second one runs into problems when a duplicate primary key is found.</p>
  
  <p>If I use REPLACE in the query, the value loaded in the first column is lost, but if I use IGNORE, the value isn't loaded in the second column. </p>
  
  <p>Is there any way to do this other than hairy text manipulation to combine all the input files into a single file?</p>