Am attempting to store values provided as int, time, hash
into Cassandra using Datastax driver.
Hash appears as { "Q17.1_4"=>"val", "Q17.2"=>"other", ...
}
Have defined table as:
I can get the PK inserted ok but am having trouble coercing the hash values into something that Cassandra can cope with.
Have created a prepared statement and using it while (trying to) looping through values:
stmt = session.prepare( "insert into forms( id, stamp, questions ) values ( ?,?,? )" )
...
json_val.each{ |key,val|
result = session.execute( stmt, val[ 'ID' ].to_i, Time.parse( val[ 'tDate' ]).to_i, val )
}
If I insert 'val' as a hash I get this error:
/lib/cassandra/statements/prepared.rb:53:in `bind': expecting exactly 3 bind parameters, 2 given (ArgumentError)
This says (to me) that there isn't a method to convert the hash to what Cassandra wants.
If I insert the val as a string (using hash.to_s
) I get this error:
/lib/cassandra/protocol/type_converter.rb:331:in
varchar_to_bytes': undefined method
encode' for 1:Fixnum (NoMethodError)
... same goes for converting it to a json string, changing double quotes to single and so on.
I can insert the values using the cqlsh (command line) ( EG insert into forms (id, stamp, questions) values ( 123, 12345678, { 'one':'two','three':'four'});
)
So the question is - how do I get this Ruby hash into a format that the Cassandra driver will accept?
Using:
EDIT:
JSON value of 'questions' hash is { "Q17.1_4":"val", "Q17.2":"other", ...}
Also - I can insert the first two columns just fine. Omitting the third value from the insert statement works so I know those two values aren't the culprit here.
Found two problems:
Last argument will be treated as options if it is a Hash. Therefore, make sure to pass empty options when executing a statement with the last parameter required to be a map datatype.
type_converter.rb:331:in
varchar_to_bytes': undefined method
encode' for 1:Fixnum (NoMethodError)
This lead me to believe that there was an invalid value in there somewhere. To fix this I created a temp hash and checked every value to make sure it was a string before adding it to this temp hash. Then using this temp value I was able to add to the DB using the stored procedure.
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