CODEWITHSUNDEEP
cassandra
srai
srai

Reputation: 1031

Select specific columns from Cassandra based on their name

I have a cassandra database in which columns can be added or removed based on the application need. The column names start with the prefix RSSI. I was wondering if it is possible to select all columns where the column name is like %RSSI%. In MYSQL you can do something like select count(*) FROM INFORMATION_SCHEMA.COLUMNS WHERE table_name ='MACTrain' AND column_name LIKE '%RSSI%'. Is it possible in cassandra ? If not what can be a solution to select columns based on a specific wildcard.

Upvotes: 1

Views: 578

Answers (1)

jorgebg
jorgebg

Reputation: 6600

You can obtain the columns metadata of a table by querying the system keyspace:

select * from system.schema_columns 
where keyspace_name = 'yourks' and columnfamily_name = 'yourtable';

For Cassandra v3.0 and above, you can use the new system_schema keyspace:

select * from system_schema.columns 
where keyspace_name = 'yourks' and table_name = 'yourtable';

Upvotes: 2

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