Re: Empty cqlsh cells vs. null
Tyler, I see. That explains it. Any chance you might know how the Datastax Java driver behaves for this (odd) case? Cheers, Jens ——— Jens Rantil Backend engineer Tink AB Email: jens.ran...@tink.se Phone: +46 708 84 18 32 Web: www.tink.se Facebook Linkedin Twitter On Friday, Oct 24, 2014 at 6:24 pm, Tyler Hobbs ty...@datastax.com, wrote: On Fri, Oct 24, 2014 at 6:38 AM, Jens Rantil jens.ran...@tink.se wrote: Just to clarify, I am seeing three types of output for an int field. It’s either: * Empty output. Nothing. Nil. Also ‘’. * An integer written in green. Regexp: [0-9]+ * Explicitly ‘null’ written in red letters. Some types (including ints) accept an empty string/ByteBuffer as a valid value. This is distinct from null, or no cell being present. This behavior is primarily a legacy from the Thrift days. -- Tyler Hobbs DataStax
Re: Empty cqlsh cells vs. null
On Mon, Oct 27, 2014 at 11:05 AM, Jens Rantil jens.ran...@tink.se wrote: Tyler, I see. That explains it. Any chance you might know how the Datastax Java driver behaves for this (odd) case? The Row.getInt() method will do as for nulls and return 0 (though of course, the Row.isNull() method will return false). If you want to explicitely check if it's an empty value, you'll have to use getBytesUnsafe(). Long story short, unless you like suffering for no reason, don't insert empty values for types for which it doesn't make sense. -- Sylvain Cheers, Jens ——— Jens Rantil Backend engineer Tink AB Email: jens.ran...@tink.se Phone: +46 708 84 18 32 Web: www.tink.se Facebook Linkedin Twitter On Friday, Oct 24, 2014 at 6:24 pm, Tyler Hobbs ty...@datastax.com, wrote: On Fri, Oct 24, 2014 at 6:38 AM, Jens Rantil jens.ran...@tink.se wrote: Just to clarify, I am seeing three types of output for an int field. It’s either: * Empty output. Nothing. Nil. Also ‘’. * An integer written in green. Regexp: [0-9]+ * Explicitly ‘null’ written in red letters. Some types (including ints) accept an empty string/ByteBuffer as a valid value. This is distinct from null, or no cell being present. This behavior is primarily a legacy from the Thrift days. -- Tyler Hobbs DataStax http://datastax.com/
Re: Empty cqlsh cells vs. null
This is interesting, because I am definitely seeing three different types of values. See attached screenshot and link. Link: https://gist.github.com/JensRantil/d162801812ca48ad3f75 Image/screenshot: https://www.dropbox.com/s/vczzgrf0vk9adzk/cqlsh-int.png?dl=0 Cheers, Jens ——— Jens Rantil Backend engineer Tink AB Email: jens.ran...@tink.se Phone: +46 708 84 18 32 Web: www.tink.se Facebook Linkedin Twitter On Thu, Oct 23, 2014 at 4:40 PM, Adam Holmberg adam.holmb...@datastax.com wrote: 'null' is how cqlsh displays empty cells: https://github.com/apache/cassandra/blob/trunk/pylib/cqlshlib/formatting.py#L47-L58 On Thu, Oct 23, 2014 at 9:36 AM, DuyHai Doan doanduy...@gmail.com wrote: Hello Jens What do you mean by cqlsh explicitely writes 'null' in those cells ? Are you seing textual value null written in the cells ? Null in CQL can have 2 meanings: 1. the column did not exist (or more precisely, has never been created) 2. the column did exist sometimes in the past (has been created) but then has been deleted (tombstones) On Thu, Oct 23, 2014 at 8:37 AM, Jens Rantil jens.ran...@tink.se wrote: Hi, Not sure this is a Datastax specific question to be asked elsewhere. In that case, let me know. Anyway, I have populated a Cassandra table from DSE Hive. When I fire up cqlsh and execute a SELECT against the table I have columns of INT type that are empty. At first I thought these were null, but it turns out that cqlsh explicitly writes null in those cells. What can I make of this? A bug in Hive serialization to Cassandra? Cheers, Jens — Sent from Mailbox https://www.dropbox.com/mailbox
Re: Empty cqlsh cells vs. null
What do you mean by “cqlsh explicitely writes ‘null’ in those cells” ? Are you seing textual value “null” written in the cells ? Just to clarify, I am seeing three types of output for an int field. It’s either: * Empty output. Nothing. Nil. Also ‘’. * An integer written in green. Regexp: [0-9]+ * Explicitly ‘null’ written in red letters. My question concerns what the difference between Empty output and ‘null’ is. I’m also curious how my Datastax Java driver will handle this, but that’ll be my next quest, I guess. Thanks, Jens ——— Jens Rantil Backend engineer Tink AB Email: jens.ran...@tink.se Phone: +46 708 84 18 32 Web: www.tink.se Facebook Linkedin Twitter On Thu, Oct 23, 2014 at 4:36 PM, DuyHai Doan doanduy...@gmail.com wrote: Hello Jens What do you mean by cqlsh explicitely writes 'null' in those cells ? Are you seing textual value null written in the cells ? Null in CQL can have 2 meanings: 1. the column did not exist (or more precisely, has never been created) 2. the column did exist sometimes in the past (has been created) but then has been deleted (tombstones) On Thu, Oct 23, 2014 at 8:37 AM, Jens Rantil jens.ran...@tink.se wrote: Hi, Not sure this is a Datastax specific question to be asked elsewhere. In that case, let me know. Anyway, I have populated a Cassandra table from DSE Hive. When I fire up cqlsh and execute a SELECT against the table I have columns of INT type that are empty. At first I thought these were null, but it turns out that cqlsh explicitly writes null in those cells. What can I make of this? A bug in Hive serialization to Cassandra? Cheers, Jens — Sent from Mailbox https://www.dropbox.com/mailbox
Re: Empty cqlsh cells vs. null
On Fri, Oct 24, 2014 at 6:38 AM, Jens Rantil jens.ran...@tink.se wrote: Just to clarify, I am seeing three types of output for an int field. It’s either: * Empty output. Nothing. Nil. Also ‘’. * An integer written in green. Regexp: [0-9]+ * Explicitly ‘null’ written in red letters. Some types (including ints) accept an empty string/ByteBuffer as a valid value. This is distinct from null, or no cell being present. This behavior is primarily a legacy from the Thrift days. -- Tyler Hobbs DataStax http://datastax.com/
Empty cqlsh cells vs. null
Hi, Not sure this is a Datastax specific question to be asked elsewhere. In that case, let me know. Anyway, I have populated a Cassandra table from DSE Hive. When I fire up cqlsh and execute a SELECT against the table I have columns of INT type that are empty. At first I thought these were null, but it turns out that cqlsh explicitly writes null in those cells. What can I make of this? A bug in Hive serialization to Cassandra? Cheers, Jens — Sent from Mailbox
Re: Empty cqlsh cells vs. null
Hello Jens What do you mean by cqlsh explicitely writes 'null' in those cells ? Are you seing textual value null written in the cells ? Null in CQL can have 2 meanings: 1. the column did not exist (or more precisely, has never been created) 2. the column did exist sometimes in the past (has been created) but then has been deleted (tombstones) On Thu, Oct 23, 2014 at 8:37 AM, Jens Rantil jens.ran...@tink.se wrote: Hi, Not sure this is a Datastax specific question to be asked elsewhere. In that case, let me know. Anyway, I have populated a Cassandra table from DSE Hive. When I fire up cqlsh and execute a SELECT against the table I have columns of INT type that are empty. At first I thought these were null, but it turns out that cqlsh explicitly writes null in those cells. What can I make of this? A bug in Hive serialization to Cassandra? Cheers, Jens — Sent from Mailbox https://www.dropbox.com/mailbox
Re: Empty cqlsh cells vs. null
'null' is how cqlsh displays empty cells: https://github.com/apache/cassandra/blob/trunk/pylib/cqlshlib/formatting.py#L47-L58 On Thu, Oct 23, 2014 at 9:36 AM, DuyHai Doan doanduy...@gmail.com wrote: Hello Jens What do you mean by cqlsh explicitely writes 'null' in those cells ? Are you seing textual value null written in the cells ? Null in CQL can have 2 meanings: 1. the column did not exist (or more precisely, has never been created) 2. the column did exist sometimes in the past (has been created) but then has been deleted (tombstones) On Thu, Oct 23, 2014 at 8:37 AM, Jens Rantil jens.ran...@tink.se wrote: Hi, Not sure this is a Datastax specific question to be asked elsewhere. In that case, let me know. Anyway, I have populated a Cassandra table from DSE Hive. When I fire up cqlsh and execute a SELECT against the table I have columns of INT type that are empty. At first I thought these were null, but it turns out that cqlsh explicitly writes null in those cells. What can I make of this? A bug in Hive serialization to Cassandra? Cheers, Jens — Sent from Mailbox https://www.dropbox.com/mailbox
