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USE users_tracking;
SELECT user_name FROM visits
where port_name IN
(SELECT port_name FROM ports where location = 'NY' )//as temp;
It gives an error
mismatched input 'SELECT' expecting RULE_T_R_PAREN
Is there any way I can store the inner query in a variable and then use that?
I tried using set@varname := query but it does not recognize the set command.
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Cassandra cannot do joins or subqueries. Rather, Casssandra emphasizes denormalization through features like collections. A column family (called "table" since CQL 3) resembles a table in a RDBMS (Relational Database Management system).
Nested queries are not allowed in Cassandra CQL. For this kind of complex querying feature you'll need to use Hive or SparkSQL.
Cassandra will request ALLOW FILTERING as it will have to first find and load the rows containing Jonathan as author, and then to filter out the ones which do not have a time2 column equal to the specified value. Adding an index on time2 might improve the query performance.
Using the SELECT command with the IN keyword. The IN keyword can define a set of clustering columns to fetch together, supporting a "multi-get" of CQL rows. A single clustering column can be defined if all preceding columns are defined for either equality or group inclusion.
Nested queries are not allowed in Cassandra CQL. For this kind of complex querying feature you'll need to use Hive or SparkSQL.
Here is a full CQL reference, http://cassandra.apache.org/doc/cql3/CQL.html
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