CODEWITHSUNDEEP
c++cassandrablobcql
Vishal Sharma
Vishal Sharma

Reputation: 1750

Blob data type in Cassandra

I don't understand much about using blob data type. I'm new in Cassandra and have just started working with Cassandra's C++ API. Can the contents of a C++ structure be stored in Cassandra's Blob. If yes, then how. For example, to store bigint as blob we've bigintAsBlob().

Upvotes: 1

Views: 405

Answers (1)

Botond Dénes
Botond Dénes

Reputation: 620

Given a struct:

struct my_struct {
    int field1;
    double field2;
};

And a prepared statement (I hope you use prepared statements), you can do this:

my_struct s;
std::unique_ptr<char[]> buffer(new char[sizeof(my_struct)]);
memcpy(buffer.get(), &s, sizeof(my_struct));
cass_statement_bind_bytes(statement, index, buffer.get(), sizeof(my_struct))

Where statement is a prepared statement and index is the index of the blob field in your schema. Note that your struct has to be a POD with no members relying on dynamic memory (e.g. no char*), otherwise this won't work. I didn't test this but I hope it helps.

Upvotes: 3

Related Questions