Hi, Try something like
SELECT CASE WHEN field1_old is not null THEN field1_old ELSE field1_renamed as field1, field2, field3 FROM yourjsonfiles; On 15 January 2018 at 04:09, Divya Gehlot <divya.htco...@gmail.com> wrote: > Hi, > I am processing json data files in Apache Drill. > > Earlier the format of files were > > { > "field2": [ > "296dOmWrTK-dunFoei2gQg" > ], > "field3": { > "name": "SE_21", > "count": 0 > }, > "field1_old": "Qsa87PoaTgCIEab0z8VmgQ", > "timestamp": 1514105922659 > } > > Later the files format changes to > > { > "field1_renamed": "OiJ4FeiMEeexdAaIPcVKTA", > "filed2": [ > "kwj5GD3EQYa1joxIWrPWEw" > ], > "filed3": { > "name": "SE_16", > "count": 0 > }, > "timestamp": 1515545336591 > > > The only change in the files data is field1_old and field1_renamed > I know I can process the files in two queries and name field 1_old and > field _renamed as field1 > I am looking for better ideas to process these files in one query . > > Thanks, > Divya >