Do you have zero length strings in your data? I have seen cases where the system option to cast empty strings to NULL doesn't work as advertised. You should re-open DRILL-3214.
When I run into this problem, I usually use a regex to workaround. The PROJECT takes a performance hit when you do this for larger data sets but it works. $cat nulls.psv date_col|string_col |test 2016-10-28|test2 $ sqlline apache drill 1.8.0 "a little sql for your nosql" 0: jdbc:drill:> select date_col, string_col from `nulls.psv`; +-------------+-------------+ | date_col | string_col | +-------------+-------------+ | | test | | 2016-10-28 | test2 | +-------------+-------------+ 2 rows selected (0.303 seconds) 0: jdbc:drill:> select to_date(date_col,'yyyy-mm-dd') from `nulls.psv`; Error: SYSTEM ERROR: IllegalArgumentException: Invalid format: "" Fragment 0:0 [Error Id: c058acbe-f2bf-4c3b-a447-66bebdc4c642 on se-node10.se.lab:31010] (state=,code=0) 0: jdbc:drill:> select case when date_col similar to '[0-9]+%' then to_date(date_col,'yyyy-MM-dd') else null end as date_col_converted from `nulls.psv`; +---------------------+ | date_col_converted | +---------------------+ | null | | 2016-10-28 | +---------------------+ 2 rows selected (0.521 seconds) 0: jdbc:drill:> alter system set `drill.exec.functions.cast_empty_string_to_null` = true; +-------+----------------------------------------------------------+ | ok | summary | +-------+----------------------------------------------------------+ | true | drill.exec.functions.cast_empty_string_to_null updated. | +-------+----------------------------------------------------------+ 1 row selected (0.304 seconds) 0: jdbc:drill:> select to_date(date_col,'yyyy-mm-dd') from `nulls.psv`; Error: SYSTEM ERROR: IllegalArgumentException: Invalid format: "" Fragment 0:0 [Error Id: 92126a1b-1c03-4e90-bc3a-01c5c81bb013 on se-node10.se.lab:31010] (state=,code=0) 0: jdbc:drill:> -Veera On Fri, Oct 28, 2016 at 9:24 AM, Khurram Faraaz <[email protected]> wrote: > All, > > Question is - why does it work for a parquet column and fails when CSV > column is used ? > > Drill 1.9.0 commit : a29f1e29 > > This is a simple project of column from a csv file, works. > {noformat} > 0: jdbc:drill:schema=dfs.tmp> select columns[4] FROM `typeall_l.csv` t1 > limit 5; > +-------------+ > | EXPR$0 | > +-------------+ > | 2011-11-04 | > | 1986-10-22 | > | 1992-09-10 | > | 2016-08-07 | > | 1986-01-25 | > +-------------+ > 5 rows selected (0.26 seconds) > {noformat} > > Using TO_DATE function with columns[x] as first input fails, with an > IllegalArgumentException > {noformat} > 0: jdbc:drill:schema=dfs.tmp> select to_date(columns[4],'yyyy-mm-dd') FROM > `typeall_l.csv` t1 limit 5; > Error: SYSTEM ERROR: IllegalArgumentException: Invalid format: "" > > Fragment 0:0 > > [Error Id: 9cff3eb9-4045-4d9a-a6a1-1eadaa597f30 on centos-01.qa.lab:31010] > (state=,code=0) > {noformat} > > However, interestingly same query over parquet column returns correct > results, on same data. > > {noformat} > 0: jdbc:drill:schema=dfs.tmp> select to_date(col_dt,'yyyy-mm-dd') FROM > typeall_l limit 5; > +-------------+ > | EXPR$0 | > +-------------+ > | 2011-01-04 | > | 1986-01-22 | > | 1992-01-10 | > | 2016-01-07 | > | 1986-01-25 | > +-------------+ > 5 rows selected (0.286 seconds) > {noformat} > > When the date string is passed as first input, to_date function returns > correct results. > {noformat} > 0: jdbc:drill:schema=dfs.tmp> select to_date('2011-01-04','yyyy-mm-dd') > from (values(1)); > +-------------+ > | EXPR$0 | > +-------------+ > | 2011-01-04 | > +-------------+ > 1 row selected (0.235 seconds) > {noformat} > > Thanks, > Khurram > -- Veera Naranammalpuram Product Specialist - SQL on Hadoop *MapR Technologies (www.mapr.com <http://www.mapr.com>)* *(Email) [email protected] <[email protected]>* *(Mobile) 917 683 8116 - can text * *Timezone: ET (UTC -5:00 / -4:00)*
