通过php查询Cassandra

Question

I am trying to do a SELECT query from Cassandra Database through a PHP script.
The connection goes through php successfully. This is the query:

$session  = $cluster->connect($keyspace);    
$result = $session->execute("SELECT * FROM twitter.tweets_by_author WHERE author= 'John Doe'")

Question 1
I will get the author name through an HTML form , let the variable be author_name . How do I pass author_name in the WHERE clause?

I have tried:

$result = $session->execute("SELECT * FROM twitter.tweets_by_author WHERE author= \%s\",author_name);

but this isn't working, most probably due to the fact that the value after = in WHERE clause needs to be in single inverted commas '' for it to be valid cassandra query.

Further, I want to print the result, something like this:

printf("  \"%s\" \"%s\" \"%s\" \"%s\" \"%s\" \n  ", $row['tid'],$row['tweet_text'], $row['author_id'], $row['location'], $row['lang']);

Question 2
Since HTML will combine extra whitespaces how do I print whitespaces according to my wish?

Answer 1

Answering Q1 only (I'm not HTML expert). You better to use so-called prepared queries as it's described in documentation . Something like this:

$prepared = $session->prepare(""SELECT * FROM twitter.tweets_by_author WHERE author= ?")
$result = $session->execute($prepared, 
      array('arguments' => array('author' => author_name)))

One of the advantages of the prepared queries is that they are parsed once on server, and then client send only the data for placeholders ( ? marks), not the full query. This gives very big performance boost. But you need to store prepared query somewhere, so it will be reused by multiple requests - it requires an additional roundtrip to server...