CQL timeuuid comparison using maxTimeuuid / minTimeuuid - cassandra

I am using Datastax cassandra distribution on Mac OS X (dsc-cassandra-1.2.6). I want to use timeuuid types, and was experimenting with queries against them.
Here is my table:
CREATE TABLE test_t (
canon_key text,
t timeuuid,
PRIMARY KEY (canon_key, t)
)
Now lets say I get a row.
cqlsh:pagedb> select canon_key, t, dateOf(t), unixTimestampOf(t) from test_t where canon_key = 'xxx' and t >= minTimeuuid('2013-08-08 18:43:58-0700');
canon_key | t | dateOf(t) | unixTimestampOf(t)
-----------+--------------------------------------+--------------------------+--------------------
xxx | 287d3c30-0095-11e3-9268-a7d2e09193eb | 2013-08-08 18:43:58-0700 | 1376012638067
Now, I want to delete this row. I don't see a good way of doing it, because there is no equality operator for the timeuuid type.
The nature of the data I am adding is such that I (possibly) wouldn't even mind doing this:
cqlsh:pagedb> select canon_key, t, dateOf(t), unixTimestampOf(t) from test_t where canon_key = 'xxx' and t >= minTimeuuid('2013-08-08 18:43:58-0700') and t <= maxTimeuuid('2013-08-08 18:43:58-0700');
But according to the documentation (http://cassandra.apache.org/doc/cql3/CQL.html#usingdates), that will not work. Quoting: " Please note that t >= maxTimeuuid('2013-01-01 00:05+0000') would still not select a timeuuid generated exactly at ‘2013-01-01 00:05+0000’ and is essentially equivalent to t > maxTimeuuid('2013-01-01 00:05+0000').".
So.. how do I delete this row?

Your premise is mistaken -- minTimeuuid and maxTimeuuid do exist to allow inequality operations on timeuuids, but that does not mean that simple equality is not supported:
cqlsh:foo> insert into test_t (canon_key, t) values ('k', now());
cqlsh:foo> select * from test_t;
canon_key | t
-----------+--------------------------------------
k | 27609890-0209-11e3-b862-59d5a2b25b8f
(1 rows)
cqlsh:foo> delete from test_t where canon_key = 'k' and t = 27609890-0209-11e3-b862-59d5a2b25b8f;
cqlsh:foo> select * from test_t;
(0 rows)

Related

How to run CQL in Zeppelin by taking input in user input format?

I was trying to run CQL query by taking in user input format in Zeppelin tool:-
%cassandra
SELECT ${Select Fields Type=uuid ,uuid | created_by | email_verify| username} FROM
${Select Table=keyspace.table_name}
${WHERE email_verify="true" } ${ORDER BY='updated_date' }LIMIT ${limit = 10};
while running this query I was getting this error:
line 4:0 mismatched input 'true' expecting EOF
(SELECT uuid FROM keyspace.table_name ["true"]...)
You need to move WHERE and ORDER BY out of the dynamic form declaration.
The input field declaration is looks as following: ${field_name=default_value}. In your case, instead of WHERE ..., you've got the field name of WHERE email_verify.
It should be as following (didn't tested):
%cassandra
SELECT ${Select Fields Type=uuid ,uuid | created_by | email_verify| username} FROM
${Select Table=keyspace.table_name}
WHERE ${where_cond=email_verify='true'} ORDER BY ${order_by='updated_date'} LIMIT ${limit = 10};
Update:
here is the working example for table with following structure:
CREATE TABLE test.scala_test2 (
id int,
c int,
t text,
tm timestamp,
PRIMARY KEY (id, c)
) WITH CLUSTERING ORDER BY (c ASC)

Cassandra : Key Level access in Map type columns

In Cassandra,Suppose we require to access key level against map type column. how to do it?
Create statement:
create table collection_tab2(
empid int,
emploc map<text,text>,
primary key(empid));
Insert statement:
insert into collection_tab2 (empid, emploc ) VALUES ( 100,{'CHE':'Tata Consultancy Services','CBE':'CTS','USA':'Genpact LLC'} );
select:
select emploc from collection_tab2;
empid | emploc
------+--------------------------------------------------------------------------
100 | {'CBE': 'CTS', 'CHE': 'Tata Consultancy Services', 'USA': 'Genpact LLC'}
In that case, if want to access 'USA' key alone . What I should do?
I tried based on the Index. But all values are coming.
CREATE INDEX fetch_index ON killrvideo.collection_tab2 (keys(emploc));
select * from collection_tab2 where emploc CONTAINS KEY 'CBE';
empid | emploc
------+--------------------------------------------------------------------------
100 | {'CBE': 'CTS', 'CHE': 'Tata Consultancy Services', 'USA': 'Genpact LLC'}
But expected:
'CHE': 'Tata Consultancy Services'
Just as a data model change I would strongly recommend:
create table collection_tab2(
empid int,
emploc_key text,
emploc_value text,
primary key(empid, emploc_key));
Then you can query and page through simply as the emploc_key is clustering key instead of part of the cql collection that has multiple limits and negative performance impacts.
Then:
insert into collection_tab2 (empid, emploc_key, emploc_value) VALUES ( 100, 'CHE', 'Tata Consultancy Services');
insert into collection_tab2 (empid, emploc_key, emploc_value) VALUES ( 100, 'CBE, 'CTS');
insert into collection_tab2 (empid, emploc_key, emploc_value) VALUES ( 100, 'USA', 'Genpact LLC');
Can also put it in a unlogged batch and it will still be applied efficiently and atomically because all in the same partition.
To do it as you have you can after 4.0 with CASSANDRA-7396 with [] selectors like:
SELECT emploc['USA'] FROM collection_tab2 WHERE empid = 100;
But I would still strongly recommend data model changes as its significantly more efficient, and can work in existing versions with:
SELECT * FROM collection_tab2 WHERE empid = 100 AND emploc_key = 'USA';

SQL Oracle Sub-query

I am having a issue getting this Sub-query to run. I am using Toad Data Point -Oracle. I get syntax error. I have tried several different ways with no luck. I am knew to sub-query's
Select *
from FINC.VNDR_ITEM_M as M
where M.ACCT_DOC_NBR = A.ACCT_DOC_NBR
(SELECT A.CLIENT_ID,
A.SRC_SYS_ID,
A.CO_CD,
A.ACCT_NBR,
A.CLR_DT,
A.ASGN_NBR,
A.FISCAL_YR,
A.ACCT_DOC_NBR,
A.LINE_ITEM_NBR,
A.MFR_PART_NBR,
A.POST_DT,
A.DRCR_IND,
A.DOC_CRNCY_AMT,
A.CRNCY_CD,
A.BSL_DT
FROM FINC.VNDR_ITEM_F A
WHERE A.CLR_DT IN (SELECT MAX(B.CLR_DT)
FROM FINC.VNDR_ITEM_F AS B
where (B.ACCT_DOC_NBR = A.ACCT_DOC_NBR and B.FISCAL_YR=A.FISCAL_YR and B.LINE_ITEM_NBR = A.LINE_ITEM_NBR and B.SRC_SYS_ID =A.SRC_SYS_ID and B.POST_DT=A.POST_DT and B.CO_CD=A.CO_CD)
and (B.CO_CD >='1000' and B.CO_CD <= '3000' or B.CO_CD ='7090') and (B.POST_DT Between to_date ('08/01/2018','mm/dd/yyyy')
AND to_date ('08/31/2018', 'mm/dd/yyyy')) and (B.SRC_SYS_ID ='15399') and (B.FISCAL_YR ='2018'))
GROUP BY
A.CLIENT_ID,
A.SRC_SYS_ID,
A.CO_CD,
A.ACCT_NBR,
A.CLR_DT,
A.ASGN_NBR,
A.FISCAL_YR,
A.ACCT_DOC_NBR,
A.LINE_ITEM_NBR,
A.MFR_PART_NBR,
A.POST_DT,
A.DRCR_IND,
A.DOC_CRNCY_AMT,
A.CRNCY_CD,
A.BSL_DT)
Your syntax is broken, you put subquery just at the end. Now it looks like:
select *
from dual as m
where a.dummy = m.dummy
(select dummy from dual)
It is in incorrect place, not joined, not aliased. What you should probably do is:
select *
from dual m
join (select dummy from dual) a on a.dummy = m.dummy
You also have some redundant, unnecessary brackets, but that's minor flaw. Full code (I cannot test it without data access):
select *
from FINC.VNDR_ITEM_M M
join (SELECT A.CLIENT_ID, A.SRC_SYS_ID, A.CO_CD, A.ACCT_NBR, A.CLR_DT, A.ASGN_NBR,
A.FISCAL_YR, A.ACCT_DOC_NBR, A.LINE_ITEM_NBR, A.MFR_PART_NBR, A.POST_DT,
A.DRCR_IND, A.DOC_CRNCY_AMT, A.CRNCY_CD, A.BSL_DT
FROM FINC.VNDR_ITEM_F A
WHERE A.CLR_DT IN (SELECT MAX(B.CLR_DT)
FROM FINC.VNDR_ITEM_F AS B
where B.ACCT_DOC_NBR = A.ACCT_DOC_NBR
and B.FISCAL_YR=A.FISCAL_YR
and B.LINE_ITEM_NBR = A.LINE_ITEM_NBR
and B.SRC_SYS_ID =A.SRC_SYS_ID
and B.POST_DT=A.POST_DT
and B.CO_CD=A.CO_CD
and (('1000'<=B.CO_CD and B.CO_CD<='3000') or B.CO_CD='7090')
and B.POST_DT Between to_date ('08/01/2018', 'mm/dd/yyyy')
AND to_date ('08/31/2018', 'mm/dd/yyyy')
and B.SRC_SYS_ID ='15399' and B.FISCAL_YR ='2018')
GROUP BY A.CLIENT_ID, A.SRC_SYS_ID, A.CO_CD, A.ACCT_NBR, A.CLR_DT, A.ASGN_NBR,
A.FISCAL_YR, A.ACCT_DOC_NBR, A.LINE_ITEM_NBR, A.MFR_PART_NBR, A.POST_DT,
A.DRCR_IND, A.DOC_CRNCY_AMT, A.CRNCY_CD, A.BSL_DT) A
on M.ACCT_DOC_NBR = A.ACCT_DOC_NBR and M.CO_CD=A.CO_CD;
You need to add an alias to the SubSelect (or Derived Table in Standard SQL):
select *
from
( select .......
) AS dt
join ....

How to do multiget in CQL3 for composite row key?

CF schema:
CREATE TABLE mytable (
upperId int,
lowerId int,
hour timestamp,
counter text,
succ int,
fail int,
PRIMARY KEY ((upperId, lowerId), hour, counter));
each record is keyed by composite id upperId:lowerid, how can I do multiget with CQL3?
This is not valid:
select * from mytable where (upperid, lowerid) in ((10000, 1), (10000, 2), (20000, 1));
I can't do this either:
select * from mytable where (upperid = 10000 and lowerid in (1, 2)) or (upperid = 20000 and lowerid = 1);
I got error: missing EOF at ')'.
Please help point to effective way to do multiget for composite row key in CQL3.
Thanks,
William
CQL does not yet support a logical "or" in select statements.
Instead, in your application your could combine the result sets from the two queries:
select * from mytable where upperid = 10000 and lowerid in (1, 2);
select * from mytable where upperid = 20000 and lowerid = 1;
Reference:
SO question: Alternative for OR condition after where clause in select statement Cassandra
Latest CQL docs

Cassandra/Hector: Add a counter on a composite primary key

I've created a table in CQL3 console (no single primary key constituent is unique, together they will be):
CREATE TABLE aggregate_logs (
bpid varchar,
jid int,
month int,
year int,
value counter,
PRIMARY KEY (bpid, jid, month, year));
then been able to update and query by using:
UPDATE aggregate_logs SET value = value + 1 WHERE bpid='1' and jid=1 and month=1 and year=2000;
This works as expected. I wanted to do the same update in Hector (in Scala):
val aggregateMutator:Mutator[Composite] = HFactory.createMutator(keyspace, compositeSerializer)
val compKey = new Composite()
compKey.addComponent(bpid, stringSerializer)
compKey.addComponent(new Integer(jid), intSerializer)
compKey.addComponent(new Integer(month), intSerializer)
compKey.addComponent(new Integer(year), intSerializer)
aggregateMutator.incrementCounter(compKey, LogsAggregateFamily, "value", 1)
but I get an error with the message:
...HInvalidRequestException: InvalidRequestException(why:String didn't validate.)
Running the query direct from hector with:
val query = new me.prettyprint.cassandra.model.CqlQuery(keyspace, compositeSerializer, stringSerializer, new IntegerSerializer())
query.setQuery("UPDATE aggregate_logs SET value = value + 1 WHERE 'bpid'=1 and jid=1 and month=1 and year=2000")
query.execute()
which gives me the error:
InvalidRequestException(why:line 1:59 mismatched input 'and' expecting EOF)
I've not seem any other examples which use a counter under a composite primary key. Is it even possible?
It's definitely possible using directly cql (both via CQLSH and C++, at least):
cqlsh:goh_master> describe table daily_caps;
CREATE TABLE daily_caps
( caps_type ascii, id ascii, value counter, PRIMARY KEY
(caps_type, id) ) WITH COMPACT STORAGE AND comment='' AND
caching='KEYS_ONLY' AND read_repair_chance=0.100000 AND
gc_grace_seconds=864000 AND replicate_on_write='true' AND
compaction_strategy_class='SizeTieredCompactionStrategy' AND
compression_parameters:sstable_compression='SnappyCompressor';
cqlsh:goh_master> update daily_caps set value=value +1 where caps_type='xp' and id ='myid';
cqlsh:goh_master> select * from daily_caps;
caps_type | id | value
-----------+------+-------
xp | myid | 1
CQL3 and the thrift API are not compatible. So creating a column family with CQL3 and accessing it with Hector or another thrift based client will not work. For more information see:
https://issues.apache.org/jira/browse/CASSANDRA-4377

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