Class: OrangeLib::CassandraHandler

Inherits:
Object
  • Object
show all
Defined in:
lib/orange_lib/cassandra_handler.rb

Instance Method Summary collapse

Constructor Details

#initialize(host, key_space) ⇒ Session

Initialize a connection to cassandra

Examples:

@__cassandra_handler ||= HMS::CassandraHandler.new('localhost', 'halo_test')

Parameters:

  • host (String) —

    ip address of the cassandra host

  • key_space (String) —

    the key_space for connection to cassandra host



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# File 'lib/orange_lib/cassandra_handler.rb', line 12

def initialize(host, key_space)
  cluster = Cassandra.cluster(hosts: [host])
  @session  = cluster.connect(key_space)
end

Instance Method Details

#execute(sql_string) ⇒ Cassandra::Result

Execute a sql statement. end

Examples:

cassandra_handler ||= HMS::CassandraHandler.new('localhost', 'halo_test')
sql = "SELECT count(*) FROM data WHERE uid in ('#{items_list}')"
result = cassandra_handler.execute(sql)
result.rows.each do |row|
num_rows = row["count"]

Parameters:

  • sql_string (String) —

    the sql statement you would like to execute

Returns:

  • (Cassandra::Result) 


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# File 'lib/orange_lib/cassandra_handler.rb', line 27

def execute(sql_string)
  @session.execute(sql_string)
end