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https://issues.apache.org/jira/browse/CASSANDRA-14853?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17177249#comment-17177249
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Adam Holmberg edited comment on CASSANDRA-14853 at 8/13/20, 6:44 PM:
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I looked at the code for this briefly and there's not a great way to do it with
the way that formatting is parameterized right now.
By default it will use [this
format|https://github.com/apache/cassandra/blob/54ebb19720225e176bc93e6dbc9e8943fa5e3bfc/pylib/cqlshlib/formatting.py#L115]
to format `datetime`.
[strptime|https://docs.python.org/3/library/datetime.html#strftime-and-strptime-format-codes]
does not provide a way of specifying precision in the pattern.
Because of the way the [format
function|https://github.com/apache/cassandra/blob/54ebb19720225e176bc93e6dbc9e8943fa5e3bfc/pylib/cqlshlib/formatting.py#L115]
is parameterized, we can't simply pick the returned string apart and remove
digits.
Separately from this, the parsing I've introduced in CASSANDRA-15976 actually
does parse the format output by cqlsh, so wrapping a value back works.
I suggest we leave this formatting alone for now and let the better parsing on
the server take care of this problem.
{noformat}
cqlsh:test> create table t1(tm timestamp primary key, t text);
cqlsh:test> insert into t1(tm, t) values(toTimestamp(now()), 't');
cqlsh:test> insert into t1(tm, t) values(toTimestamp(now()), 't2');
cqlsh:test> select * from t1;
tm | t
---------------------------------+----
2020-08-13 18:38:34.598000+0000 | t2
2020-08-13 18:38:27.266000+0000 | t
(2 rows)
cqlsh:test> select * from t1 where tm = '2020-08-13 18:38:34.598000+0000';
tm | t
---------------------------------+----
2020-08-13 18:38:34.598000+0000 | t2
(1 rows)
cqlsh:test>
{noformat}
wdyt?
was (Author: aholmber):
I looked at the code for this briefly and there's not a great way to do it with
the way that formatting is parameterized right now.
By default it will use [this
format|https://github.com/apache/cassandra/blob/54ebb19720225e176bc93e6dbc9e8943fa5e3bfc/pylib/cqlshlib/formatting.py#L115]
to format `datetime`.
[strptime|https://docs.python.org/3/library/datetime.html#strftime-and-strptime-format-codes]
does not provide a way of specifying precision in the pattern.
Because of the way the [format
function|https://github.com/apache/cassandra/blob/54ebb19720225e176bc93e6dbc9e8943fa5e3bfc/pylib/cqlshlib/formatting.py#L115]
is parameterized, we can't simply pick the returned string apart and remove
digits.
Separately from this, the parsing I've introduced in CASSANDRA-15976 actually
does parse the format output by cqlsh, so wrapping a value back works.
I suggest we leave this formatting alone for now and let the better parsing on
the server take care of this problem.
{noformat}
cqlsh:test> create table t1(tm timestamp primary key, t text);
cqlsh:test> insert into t1(tm, t) values(toTimestamp(now()), 't');
cqlsh:test> insert into t1(tm, t) values(toTimestamp(now()), 't2');
cqlsh:test> select * from t1;
tm | t
-----------------------------+----
2020-08-13 18:38:34.3f+0000 | t2
2020-08-13 18:38:27.3f+0000 | t
(2 rows)
cqlsh:test> select * from t1 where tm = '2020-08-13 18:38:34.598000+0000';
tm | t
---------------------------------+----
2020-08-13 18:38:34.598000+0000 | t2
(1 rows)
cqlsh:test>
{noformat}
wdyt?
> Change default timestamp format to output only milliseconds, not microseconds
> -----------------------------------------------------------------------------
>
> Key: CASSANDRA-14853
> URL: https://issues.apache.org/jira/browse/CASSANDRA-14853
> Project: Cassandra
> Issue Type: Improvement
> Components: Tool/cqlsh
> Environment: Reproduced in trunk
> Reporter: Alex Ott
> Priority: Normal
> Labels: cqlsh
>
> By default cqlsh outputs the timestamp column with microseconds precision,
> like this:
> {noformat}
> cqlsh:test> create table t1(tm timestamp primary key, t text);
> cqlsh:test> insert into t1(tm, t) values(toTimestamp(now()), 't');
> cqlsh:test> insert into t1(tm, t) values(toTimestamp(now()), 't2');
> cqlsh:test> SELECT * from t1;
> tm | t
> ---------------------------------+----
> 2018-10-27 18:01:54.738000+0000 | t2
> 2018-10-27 18:01:52.599000+0000 | t
> (2 rows)
> {noformat}
> But if I want to use the value that is output on the screen in my query, I
> get an error:
> {noformat}
> cqlsh:test> select * from t1 where tm = '2018-10-27 18:01:54.738000+0000';
> InvalidRequest: Error from server: code=2200 [Invalid query] message="Unable
> to coerce '2018-10-27 18:01:54.738000+0000' to a formatted date (long)"
> {noformat}
> But if I manually round it to milliseconds, then everything works:
> {noformat}
> cqlsh:test> select * from t1 where tm = '2018-10-27 18:01:54.738+0000';
> tm | t
> ---------------------------------+----
> 2018-10-27 18:01:54.738000+0000 | t2
> (1 rows)
> {noformat}
> It would be much easier user's experience if we use the same format for
> output & input data, because right now this leads to errors, that often not
> really understandable by novice users.
> P.S. I know about cqlshrc, but not every user has it configured.
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