I want to ask cassandra to filter its results by a list of arguments. But this is not possible on a "normal" column. Or in cassandra's words:
IN predicates on non-primary-key columns (access_right_id) is not yet supported
My table looks like this:
CREATE TABLE "service"
(
course_id uuid,
type text,
access_token uuid,
name_de text,
name_en text,
url text,
edit_right_id uuid,
access_right_id uuid,
PRIMARY KEY (course_id, type, access_token)
);
I want to execute a query like this:
SELECT * FROM service WHERE
course_id = :courseId
AND type = :type
AND access_right_id IN :rights
I am now searching for a solution to my problem. I am thinking of three possible solutions:
Send N times the query (maybe with a materialized view and access_right_id as a primary key part (clustering key))
SELECT * FROM service WHERE
course_id = :courseId
AND type = :type
AND access_right_id = :right
Send a generated query like this:
SELECT * FROM service WHERE
course_id = :courseId
AND type = :type
AND (access_right_id = :right1 OR access_right_id = :right2 OR access_right_id = :right ...)
Send a query without filtering and filter the result in code.
What do you this is best in this case? What is more cassandra "compliant"?
Thank you in advance for your input.
Related
Is there there any way to query on a SET type(or MAP/LIST) to find does it contain a value or not?
Something like this:
CREATE TABLE test.table_name(
id text,
ckk SET<INT>,
PRIMARY KEY((id))
);
Select * FROM table_name WHERE id = 1 AND ckk CONTAINS 4;
Is there any way to reach this query with YCQL api?
And can we use a SET type in SECONDRY INDEX?
Is there any way to reach this query with YCQL api?
YCQL does not support the CONTAINS keyword yet (feel free to open an issue for this on the YugabyteDB GitHub).
One workaround can be to use MAP<INT, BOOLEAN> instead of SET<INT> and the [] operator.
For instance:
CREATE TABLE test.table_name(
id text,
ckk MAP<int, boolean>,
PRIMARY KEY((id))
);
SELECT * FROM table_name WHERE id = 'foo' AND ckk[4] = true;
And can we use a SET type in SECONDRY INDEX?
Generally, collection types cannot be part of the primary key, or an index key.
However, "frozen" collections (i.e. collections serialized into a single value internally) can actually be part of either primary key or index key.
For instance:
CREATE TABLE table2(
id TEXT,
ckk FROZEN<SET<INT>>,
PRIMARY KEY((id))
) WITH transactions = {'enabled' : true};
CREATE INDEX table2_idx on table2(ckk);
Another option is to use with compound primary key and defining ckk as clustering key:
cqlsh> CREATE TABLE ybdemo.tt(id TEXT, ckk INT, PRIMARY KEY ((id), ckk)) WITH CLUSTERING ORDER BY (ckk DESC);
cqlsh> SELECT * FROM ybdemo.tt WHERE id='foo' AND ckk=4;
I have Following Data Model :-
campaigns {
id int PRIMARY KEY,
scheduletime text,
SchduleStartdate text,
SchduleEndDate text,
enable boolean,
actionFlag boolean,
.... etc
}
Here i need to fetch the data basing on start date and end data with out ALLOW FILTERING .
I got more suggestions to re-design schema to full fill the requirement But i cannot filter the data basing on id since i need the data in b/w the dates .
Some one give me a good suggestion to full fill this scenario to execute Following Query :-
select * from campaings WHERE startdate='XXX' AND endDate='XXX' ; // With out Allow Filtering thing
CREATE TABLE campaigns (
SchduleStartdate text,
SchduleEndDate text,
id int,
scheduletime text,
enable boolean,
PRIMARY KEY ((SchduleStartdate, SchduleEndDate),id));
You can make the below queries to the table,
slect * from campaigns where SchduleStartdate = 'xxx' and SchduleEndDate = 'xx'; -- to get the answer to above question.
slect * from campaigns where SchduleStartdate = 'xxx' and SchduleEndDate = 'xx' and id = 1; -- if you want to filter the data again for specific ids
Here the SchduleStartdate and SchduleEndDate is used as the Partition Key and the ID is used as the Clustering key to make sure the entries are unique.
By this way, you can filter based on start, end and then id if needed.
One downside with this will be if you only need to filter by id that wont be possible as you need to first restrict the partition keys.
I have a case class which represents partition key values.
case class UserKeys (bucket:Int,
email: String)
I create query Clauses as follows:
def conditions(id: UserKeys):List[Clauses] = List(
QueryBuilder.eq("bucket", id.bucket), //TODOM - pick table description from config/env file.
QueryBuilder.eq("email", id.email)
)
And use the query as follows
val selectStmt =
select()
.from(tablename)
.where(QueryBuilder.eq(partitionKeyColumns(0), whereClauseList(0))).and(QueryBuilder.eq(partitionKeyColumns(1), whereClauseList(1)))
.limit(1)
I am getting following error.
com.datastax.driver.core.exceptions.InvalidTypeException: Value 0 of type class com.datastax.driver.core.querybuilder.Clause$SimpleClause does not correspond to any CQL3 type
Question 1 - What am I doing wrong?
The query works on cqlsh
The table I am querying is
CREATE TABLE users (
bucket int,
email text,
firstname text,
lastname text,
authprovider text,
password text,
PRIMARY KEY ((bucket, email), firstname, lastname)
Question 2 - Is there a way to print the List which contains the query clauses? I tried it but I get this incomprehensible text.
List(com.datastax.driver.core.querybuilder.Clause$SimpleClause#2389b3ee, com.datastax.driver.core.querybuilder.Clause$SimpleClause#927f81)
My bad, I was using the query clauses incorrectly. Rather than
.where(QueryBuilder.eq(partitionKeyColumns(0), whereClauseList(0))).and(QueryBuilder.eq(partitionKeyColumns(1), whereClauseList(1)))
I needed to do
.where(whereClauseList(0)).and(whereClauseList(1))
because the List already has QueryBuilder.eq("bucket", id.bucket) part
my aim is to get the msgAddDate based on below query :
select max(msgAddDate)
from sampletable
where reportid = 1 and objectType = 'loan' and msgProcessed = 1;
Design 1 :
here the reportid, objectType and msgProcessed may not be unique. To add the uniqueness I have added msgAddDate and msgProcessedDate (an additional unique value).
I use this design because I don't perform range query.
Create table sampletable ( reportid INT,
objectType TEXT,
msgAddDate TIMESTAMP,
msgProcessed INT,
msgProcessedDate TIMESTAMP,
PRIMARY KEY ((reportid ,msgProcessed,objectType,msgAddDate,msgProcessedDate));
Design 2 :
create table sampletable (
reportid INT,
objectType TEXT,
msgAddDate TIMESTAMP,
msgProcessed INT,
msgProcessedDate TIMESTAMP,
PRIMARY KEY ((reportid ,msgProcessed,objectType),msgAddDate, msgProcessedDate))
);
Please advice which one to use and what will be the pros and cons between two based on performance.
Design 2 is the one you want.
In Design 1, the whole primary key is the partition key. Which means you need to provide all the attributes (which are: reportid, msgProcessed, objectType, msgAddDate, msgProcessedDate) to be able to query your data with a SELECT statement (which wouldn't be useful as you would not retrieve any additional attributes than the one you already provided in the WHERE statemenent)
In Design 2, your partition key is reportid ,msgProcessed,objectType which are the three attributes you want to query by. Great. msgAddDate is the first clustering column, which will be automatically sorted for you. So you don't even need to run a max since it is sorted. All you need to do is use LIMIT 1:
SELECT msgAddDate FROM sampletable WHERE reportid = 1 and objectType = 'loan' and msgProcessed = 1 LIMIT 1;
Of course, make sure to define a DESC sorted order on msgAddDate (I think by default it is ascending...)
Hope it helps!
SELECT count(*) FROM device_stats
WHERE orgid = 'XYZ'
AND regionid = 'NY'
AND campusid = 'C1'
AND buildingid = 'C1'
AND floorid = '2'
AND year = 2017;
The above CQL query returns correct result - 32032, in CQL Shell
But when I run the same query using QueryBuilder Java API , I see the count as 0
BuiltStatement summaryQuery = QueryBuilder.select()
.countAll()
.from("device_stats")
.where(eq("orgid", "XYZ"))
.and(eq("regionid", "NY"))
.and(eq("campusid", "C1"))
.and(eq("buildingid", "C1"))
.and(eq("floorid", "2"))
.and(eq("year", "2017"));
try {
ResultSetFuture tagSummaryResults = session.executeAsync(tagSummaryQuery);
tagSummaryResults.getUninterruptibly().all().stream().forEach(result -> {
System.out.println(" totalCount > "+result.getLong(0));
});
I have only 20 partitions and 32032 rows per partition.
What could be the reason QueryBuilder not executing the query correctly ?
Schema :
CREATE TABLE device_stats (
orgid text,
regionid text,
campusid text,
buildingid text,
floorid text,
year int,
endofwindow timestamp,
categoryid timeuuid,
devicestats map<text,bigint>,
PRIMARY KEY ((orgid, regionid, campusid, buildingid, floorid,year),endofwindow,categoryid)
) WITH CLUSTERING ORDER BY (endofwindow DESC,categoryid ASC);
// Using the keys function to index the map keys
CREATE INDEX ON device_stats (keys(devicestats));
I am using cassandra 3.10 and com.datastax.cassandra:cassandra-driver-core:3.1.4
Moving my comment to an answer since that seems to solve the original problem:
Changing .and(eq("year", "2017")) to .and(eq("year", 2017)) solves the issue since year is an int and not a text.