I am trying to "Upsert" data into my table with CQLSSTableWriter. Everything works fine, except for my static column not being set correctly. They end up being null for every occasion. My static column is defined as brand TEXT static.
After failing with the CQLSSTableWriter, I went into the cqlsh and tried to update the static column manually:
update keyspace.data set brand='Nestle' where id = 'whatever' and date = '2015-10-07';
and with a batch as well (even though it should not matter)
begin batch
update keyspace.data set brand='Nestle' where id = 'whatever' and date = '2015-10-07';
apply batch;
My "brand" column still shows null when I retrieve some of my data (select * from keyspace.data LIMIT 100;)
My entire schema:
CREATE TABLE keyspace.data (
id text,
date text,
ts timestamp,
id_two text,
brand text static,
latitude double,
longitude double,
signals_double map<text, double>,
signals_string map<text, text>,
name text static,
PRIMARY KEY ((id, date), ts, id_two)
) WITH CLUSTERING ORDER BY (ts ASC, id_two ASC);
The reason why I chose Update instead of Insert is because I have collections that I do not want to overwrite, but rather add more elements to. Using insert would overwrite the previously stored elements of my collections.
Why can I not set a static column with an Update query?
Related
I have a table PatientRegistration with Columns
ID INTEGER PRIMARY KEY AUTOINCREMENT,
NAME VARCHAR,
PHONE TEXT,
AGE BLOB,
TURNNUMBER INT,
REG_DATE DATE TIME
I have been having troubles trying to automatically declare TURNNUMBER and assign it 0(zero) if it's null else increase it by +1 with respect to date, this is correct but only in SQL
declare #turn tinyint,
#turn=isnull((select top 1 pa.turn from PatientRegistration pa where Day(pa.Reg_Date)=#day order by pa.ID desc),0)+1
How can I achieve this using SQLite,,,, please
Edit: this should happen each a new patient is added
I am trying to model a table of content which has a timestamp, ordered by the timestamp. However I want that timestamp to change if a user decides to edit the content, (so that the content reappears at the top of the list).
I know that you can't change a primary key column so I'm at a loss of how something like this would be structured. Below is a sample table.
CREATE TABLE content(
id uuid
category text
last_update_time timestamp
PRIMARY KEY((category, id),last_update_time)) WITH CLUSTERING ORDER BY (last_update_time);
How should I model this table if I want the data to be ordered by a column that can change?
2 solutions
1) If you don't care having update history
CREATE TABLE content(
id uuid
category text
last_update_time timestamp
PRIMARY KEY((category, id))
// Retrieve last update
SELECT * FROM content WHERE category = 'xxx' AND id = yyy;
2) If you want to keep an history of updates
CREATE TABLE content(
id uuid
category text
last_update_time timestamp
PRIMARY KEY((category, id),last_update_time)) WITH CLUSTERING ORDER BY (last_update_time DESC);
// Retrieve last update
SELECT * FROM content WHERE category = 'xxx' AND id = yyy LIMIT 1;
I have a column family and syntax like this:
CREATE TABLE sr_number_callrecord (
id int,
callerph text,
sr_number text,
callid text,
start_time text,
plan_id int,
PRIMARY KEY((sr_number), start_time, callerph)
);
I want to do the query like :
a) select * from dummy where sr_number='+919xxxx8383'
and start_time >='2014-12-02 08:23:18' limit 10;
b) select * from dummy where sr_number='+919xxxxxx83'
and start_time >='2014-12-02 08:23:18'
and callerph='+9120xxxxxxxx0' limit 10;
First query works fine but second query is giving error like
Bad Request: PRIMARY KEY column "callerph" cannot be restricted
(preceding column "start_time" is either not restricted or by a non-EQ
relation)
If I get the result in first query, In second query I am just adding one
more cluster key to get filter result and the row will be less
Just like you cannot skip PRIMARY KEY components, you may only use a non-equals operator on the last component that you query (which is why your 1st query works).
If you do need to serve both of the queries you have listed above, then you will need to have separate query tables for each. To serve the second query, a query table (with the same columns) will work if you define it with a PRIMARY KEY like this:
PRIMARY KEY((sr_number), callerph, start_time)
That way you are still specifying the parts of your PRIMARY KEY in order, and your non-equals condition is on the last PRIMARY KEY component.
There are certain restrictions in the way the primary key columns are to be used in the where clause http://docs.datastax.com/en/cql/3.1/cql/cql_reference/select_r.html
One solution that will work in your situation is to change the order of clustering columns in the primary key
CREATE TABLE sr_number_callrecord (
id int,
callerph text,
sr_number text,
callid text,
start_time text,
plan_id int,
PRIMARY KEY((sr_number), callerph, start_time,)
);
Now you can use range query on the last column as
select * from sr_number_callrecord where sr_number = '1234' and callerph = '+91123' and start_time >= '1234';
I have the following Apache Cassandra Table working.
CREATE TABLE user_songs (
member_id int,
song_id int,
title text,
timestamp timeuuid,
album_id int,
album_title text,
artist_names set<text>,
PRIMARY KEY ((member_id, song_id), title)
) WITH CLUSTERING ORDER BY (title ASC)
CREATE INDEX user_songs_member_id_idx ON music.user_songs (member_id);
When I try to do a select * FROM user_songs WHERE member_id = 1; I thought the Clustering Order by title would have given me a sorted ASC of the return - but it doesn't
Two questions:
Is there something with the table in terms of ordering or PK?
Do I need more tables for my needs in order to have a sorted title by member_id.
Note - my Cassandra queries for this table are:
Find all songs with member_id
Remove a song from memeber_id given song_id
Hence why the PK is composite
UPDATE
It is simialr to: Query results not ordered despite WITH CLUSTERING ORDER BY
However one of the suggestion in the comments is to put member_id,song_id,title as primary instead of the composite that I currently have. When I do that It seems that I cannot delete with only song_id and member_id which is the data that I get for deleting (hence title is missing when deleting)
I'm working on Cassandra, trying to get to know how it works. Encountered something strange while using IN operator. Example:
Table:
CREATE TABLE test_time (
name text,
age int,
time timeuuid,
"timestamp" timestamp,
PRIMARY KEY ((name, age), time)
)
I have inserted few dummy data. Used IN operator as follows:
SELECT * from test_time
where name="9" and age=81
and time IN (c7c88000-190e-11e4-8000-000000000000, c7c88000-190e-11e4-7000-000000000000);
It worked properly.
Then, added a column of type Map. Table will look like:
CREATE TABLE test_time (
name text,
age int,
time timeuuid,
name_age map<text, int>,
"timestamp" timestamp,
PRIMARY KEY ((name, age), time)
)
On executing same query, I got following error:
Bad Request: Cannot restrict PRIMARY KEY part time by IN relation as a collection is selected by the query
From the above examples, we can say, IN operator doesn't work if there are any column of type collection(Map or List) in the table.
I don't understand why it behaves like this. Please let me know If I'm missing anything here. Thanks in advance.
Yup...that is a limitation. You can do the following:
select * from ...where name='9' and age=81 and time > x and time < y
select [columns except collection] from ...where name='9' and age=81 and time in (...)
You can then filter client side, or do another query.
You can either include your column as a part of partitioning expression in the primary key
CREATE TABLE test_time (
name text,
age int,
time timeuuid,
"timestamp" timestamp,
PRIMARY KEY ((name, time), age)
);
or create a separate Materialized View to satisfy your query requirements:
CREATE MATERIALIZED VIEW test_time_mv AS
SELECT * FROM test_time
WHERE name IS NOT NULL AND time IS NOT NULL AND age IS NOT NULL
PRIMARY KEY ((name, time), age);
Now use the Materialized View in your query instead of the base table:
SELECT * from test_time_mv
where name='9'
and age=81
and time IN (c7c88000-190e-11e4-8000-000000000000,
c7c88000-190e-11e4-7000-000000000000);