title: Alter column data type in Hive
body: <p>we need to alter the table column data  type from string to date. While am trying to do am getting the below error. Could you please help.</p>
  
  <blockquote>
    <p>hive> describe  sales_staging;</p>
    
    <p>OK</p>
    
    <p>cust_id             string               prod_num             string<br>
    qty                 int                 sale_date           string    </p>
    
    <p>sale_id             string
    Time taken: 0.151 seconds,
    Fetched: 5 row(s)</p>
    
    <p>hive> alter table sales_staging CHANGE  sale_date sale_date DATE ;</p>
    
    <p>FAILED: Execution Error, return code 1 from
    org.apache.hadoop.hive.ql.exec.DDLTask. Unable to alter table. The
    following columns have types incompatible with the existing columns in
    their respective positions :sale_date</p>
    
    <p>hive></p>
  </blockquote>