Re: Newbie question - fetching multiple columns of different datatypes and conversion from byte[]
Should the different datatype col values or names be first read as byte buffer then converted to appropriate type using Hector's provided serializers api like the way shown below ? ByteBuffer bb; .. String s= StringSerializer.get().fromByteBuffer(bb); Or are there any better ways ?
Re: Newbie question - fetching multiple columns of different datatypes and conversion from byte[]
In the case where you have different value types within the same slice, yes, you must handle the conversion yourself and ByteBufferSerializer is the easiest way to do that. On Fri, Dec 24, 2010 at 10:44 PM, Roshan Dawrani roshandawr...@gmail.com wrote: Hi, I am new to Cassandra and Hector and have a basic question on fetching multiple columns of a row that have mixed data types. So, I am basically doing equivalent of Select dateCol1, dateCol2, stringCol1, intCol1 from a_table where key in (?, ?, ?...) My question is do I need to do the conversion of columns from byte[] to Date/String/Int myself after taking out data from the ColumnSlice? For saving the same data, while adding the columns, I was able to tell which serializer to use, but slice queries seem to take only one ValueSerializer for all columns being retrieved. So, if I have got it correctly, I can only use ByteBufferSerializer in the Hector API slice query call and then do further data-type specific conversion myself at the app level? -- Roshan Blog: http://roshandawrani.wordpress.com/ Twitter: @roshandawrani Skype: roshandawrani
Re: Newbie question - fetching multiple columns of different datatypes and conversion from byte[]
Or you can specify the types with the column name instead of doing a slice. On Fri, Dec 24, 2010 at 11:23 PM, Nate McCall n...@riptano.com wrote: In the case where you have different value types within the same slice, yes, you must handle the conversion yourself and ByteBufferSerializer is the easiest way to do that. On Fri, Dec 24, 2010 at 10:44 PM, Roshan Dawrani roshandawr...@gmail.com wrote: Hi, I am new to Cassandra and Hector and have a basic question on fetching multiple columns of a row that have mixed data types. So, I am basically doing equivalent of Select dateCol1, dateCol2, stringCol1, intCol1 from a_table where key in (?, ?, ?...) My question is do I need to do the conversion of columns from byte[] to Date/String/Int myself after taking out data from the ColumnSlice? For saving the same data, while adding the columns, I was able to tell which serializer to use, but slice queries seem to take only one ValueSerializer for all columns being retrieved. So, if I have got it correctly, I can only use ByteBufferSerializer in the Hector API slice query call and then do further data-type specific conversion myself at the app level? -- Roshan Blog: http://roshandawrani.wordpress.com/ Twitter: @roshandawrani Skype: roshandawrani -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com
