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Can I use INNER JOIN in Cassandra ?
SELECT * FROM device,device_token WHERE device_token.id_phone = device.id
If I cannot use inner join. What type of query I can use in cassandra instead for inner join?
There are no joins in Cassandra.
Most people denormalize i.e. insert the data multiple times into the rows where it is needed. Cassandra is designed for extremely fast writes so increasing the insert workload is normally a good tradeoff.
You can also do a separate query and join manually, but this is normally slower.
You can use collections to model joins. Look as set, list, map and docs about it: http://www.datastax.com/docs/1.2/cql_cli/using/collections
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I have two tables stored on phpmyadmin, 'gigs' and 'bands'.
gigs: "gigID, gigBand, gigDate"
bands: "bandID, bandName, bandGenre...."
gigBand is a integer which corresponds to the bandID. I am aiming to diplay all the available gigs, but show the actual band name rather than the number. I have read table joins are the easiest way of doing this, and I have no trouble displaying the data of 'gigs' on the webpage.
But managing to display the name rather than the value is proving very difficult.
Any advice, or even an example of the code would be greatly appreciated.
You need to use a MySQL JOIN to pull the records of two related tables.
http://dev.mysql.com/doc/refman/5.7/en/join.html
SELECT * from gigs
INNER JOIN bands ON gigBand = bandID
This is pretty basic stuff though, so I would strongly recommend taking the time to do a bit more research. This seems like a good place to start:
http://www.tutorialspoint.com/mysql/index.htm
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I have a table wich contains:
RO;DE;ES;AU;IT;
How display data where DE is show on table! I need for milions queries!
It seems like you have multiple values in the same "cell". You will need to process the string. One way is to use wildcards:
SELECT something FROM something WHERE field LIKE '%DE%'
Please note however that your table design is absolutely terrible. It violates the first normal form. You should never have multiple values in a single cell that you then have to split using wildcards or other string functions. This adds overhead to your queries and will slow them down significantly. You say that you have millions of records, the impact of not having separate values has the potential to be quite large.
You should definitely think of breaking those strings into multiple records if you can.
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if i write query like this
SELECT student.name, class.subj
FROM student
INNER JOIN class
ON student.class_id = class.class_id;
in MySql so how i can write for mongoDB script ?
MongoDB does not support joins because join operations make database response slower. You should change your thinking style while designing a database. If you use your documents together, it is suggested to make them embedded documents. Here is a tip for designing based on relations :
http://docs.mongodb.org/manual/applications/data-models-relationships/
Some of data modeling documents are below :
http://docs.mongodb.org/manual/data-modeling/
http://www.toadworld.com/platforms/nosql/w/wiki/349.mongodb-data-modeling.aspx#Collection
http://highlyscalable.wordpress.com/2012/03/01/nosql-data-modeling-techniques/
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I want to populate my MSSQL database, so, I will run some procedures with random data. I have to get the parameters of every SP. How I can do that?
Thanks.
You can find it with simple query -
SELECT p.name
FROM sys.objects o
INNER JOIN sys.parameters p ON p.[object_id] = o.[object_id]
WHERE o.[name] = 'stored_proc_name' AND o.[type] = 'P'
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I am unable to delete data from multiple MySQL tables using following query;
$rel=$_POST['releaseno'];
$sql="DELETE from `tbl_uat`,`tbl_fault` WHERE `tbl_uat`.`release`='$rel' AND `tbl_fault`.`release_no`='$rel'";
I think there is a problem with the query, can any one please identify where's the problem.
Kind Regards
You need to tell the DB from which tables you want to delete by doing delete u,f from ...
$rel = mysql_real_escape_string($_POST['releaseno']);
DELETE u, f
from tbl_uat u, tbl_fault f
WHERE u.release = '$rel'
AND f.release_no = '$rel'
You also need to escape your user input before inserting into your query!