Re: is this correct, thrift unportable to CQL3Š.
On Tue, Sep 24, 2013 at 7:24 PM, Hiller, Dean dean.hil...@nrel.gov wrote:
Java has Integer as opposed to int which is what I represent golf scores
with so to speak in my example. In this case, Integer can be null but of
course maps to empty just fine. What about querying for all golf scores
that are empty then?
The DataStax java driver already maps a null Integer to a null CQL3
column, and so it *cannot* also map it to an empty value. And even though
you cannot have null CQL3 columns in the primary key, mapping a null
Integer to an empty value would be highly confusing/inconsistent (from the
point of view of the java driver) because:
1) having a null Integer map differently depending on whether the receiving
column is in the PK or not would be messy/surprising.
2) it's not really technically possible because internally the driver does
not always have the information of whether the receiving column is in the
PK or not
3) what about strings? Should we also map a null String to an empty value
when the column is in the PK? Because that would mean mapping a null java
String to an empty CQL3 string value and that just feel wrong. And if we
don't do it, then it means we treat Integer and String differently with
respect to null and that's too would be pretty confusing.
But anyway, all of that is pretty specific to the java driver, so maybe if
you guys want to debate that further we should move to the driver mailing
list:
https://groups.google.com/a/lists.datastax.com/forum/#!forum/java-driver-user
--
Sylvain
Ie. This sounds like this solution would be perfect if we can get rid of
the exception piece.
Thanks much!!!
Dean
From: Sylvain Lebresne sylv...@datastax.commailto:sylv...@datastax.com
Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org
user@cassandra.apache.orgmailto:user@cassandra.apache.org
Date: Tuesday, September 24, 2013 10:58 AM
To: user@cassandra.apache.orgmailto:user@cassandra.apache.org
user@cassandra.apache.orgmailto:user@cassandra.apache.org
Subject: Re: is this correct, thrift unportable to CQL3Š.
On Tue, Sep 24, 2013 at 6:17 PM, Vikas Goyal vi...@easility.commailto:
vi...@easility.com wrote:
Ok. Great. It works for String and Decimal/Float but not for integer data
type..
i.e,, if I am passing to the composite key column which is either text
or float, it works..
session.execute(boundStatement.bind(rowkey, , ByteBuffer.wrap(value)));
But not working with bigint, int or varint..and getting following
exception;
Exception:Invalid type for value 1 of CQL type varint, expecting class
java.math.BigInteger but class java.lang.String provided
..I am exploring more though..
We're getting into details of the java driver at this point. For int, what
you can do is:
boundStatement.setString(id, rowkey);
boundStatement.setBytesUnsafe(columnname, ByteBuffer.wrap(new
byte[0]));
boundStatement.setBytes(columnvalue, ByteBuffer.wrap(value));
In other words, the shorthand BoundStatement.bind() won't let you insert
an empty value for types
that don't naturally have an empty value (like int; keep in mind that an
empty value is not the same
than null). But you can circumvent that using setBytesUnsafe if you really
want.
Long story short, my advice would be to avoid using empty values for type
that don't naturally have
one (anything else than text and blob really). If you do, that's going to
be painful (but possible) to
work with, at least with the java driver (but for good reasons, java just
doesn't have a good to
represent an empty int value (again, you can have a null Integer but
that's different)).
--
Sylvain
Thanks a ton,
Vikas Goyal
On Tue, Sep 24, 2013 at 9:05 PM, Sylvain Lebresne sylv...@datastax.com
mailto:sylv...@datastax.com wrote:
However,we tried missing the value but it didn't work :(
Right, because not providing a value is akin to having a null value (in
the CQL3 sense of the term, which is different from what Dean asked about)
and null values are not allowed for primary key columns.
You could however insert an *empty* value if you wanted, which in you case
is just inserting an empty string since colname is a string. Thrift doesn't
allow more or less in that case.
--
Sylvain
So our code is like below where we are using 3 values if colname is not
null..else 2 values..
if (key != null) {
PreparedStatement statement = session.prepare(INSERT INTO
keys.StringIndice (id, colname, colvalue) VALUES (?, ?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), key, ByteBuffer.wrap(value)));
} else {
PreparedStatement statement = session.prepare(INSERT INTO
+ keys + . + table + (id, colvalue) VALUES (?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute
Re: is this correct, thrift unportable to CQL3Š.
On Wed, Sep 25, 2013 at 12:22 AM, Sylvain Lebresne sylv...@datastax.comwrote:
On Tue, Sep 24, 2013 at 7:24 PM, Hiller, Dean dean.hil...@nrel.govwrote:
Java has Integer as opposed to int which is what I represent golf
scores with so to speak in my example. In this case, Integer can be null
but of course maps to empty just fine. What about querying for all golf
scores that are empty then?
The DataStax java driver already maps a null Integer to a null CQL3
column, and so it *cannot* also map it to an empty value. And even though
you cannot have null CQL3 columns in the primary key, mapping a null
Integer to an empty value would be highly confusing/inconsistent (from the
point of view of the java driver) because:
1) having a null Integer map differently depending on whether the
receiving column is in the PK or not would be messy/surprising.
2) it's not really technically possible because internally the driver does
not always have the information of whether the receiving column is in the
PK or not
3) what about strings? Should we also map a null String to an empty value
when the column is in the PK? Because that would mean mapping a null java
String to an empty CQL3 string value and that just feel wrong. And if we
don't do it, then it means we treat Integer and String differently with
respect to null and that's too would be pretty confusing.
But anyway, all of that is pretty specific to the java driver, so maybe if
you guys want to debate that further we should move to the driver mailing
list:
https://groups.google.com/a/lists.datastax.com/forum/#!forum/java-driver-user
Nulls should definitely stay null (that's an old DB debate), but if this
is a generic case, we might consider adding an emptyValue() helper method.
Would that be possible Sylvain?
--
Sylvain
Ie. This sounds like this solution would be perfect if we can get rid of
the exception piece.
Thanks much!!!
Dean
From: Sylvain Lebresne sylv...@datastax.commailto:sylv...@datastax.com
Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org
user@cassandra.apache.orgmailto:user@cassandra.apache.org
Date: Tuesday, September 24, 2013 10:58 AM
To: user@cassandra.apache.orgmailto:user@cassandra.apache.org
user@cassandra.apache.orgmailto:user@cassandra.apache.org
Subject: Re: is this correct, thrift unportable to CQL3Š.
On Tue, Sep 24, 2013 at 6:17 PM, Vikas Goyal vi...@easility.commailto:
vi...@easility.com wrote:
Ok. Great. It works for String and Decimal/Float but not for integer data
type..
i.e,, if I am passing to the composite key column which is either text
or float, it works..
session.execute(boundStatement.bind(rowkey, , ByteBuffer.wrap(value)));
But not working with bigint, int or varint..and getting following
exception;
Exception:Invalid type for value 1 of CQL type varint, expecting class
java.math.BigInteger but class java.lang.String provided
..I am exploring more though..
We're getting into details of the java driver at this point. For int,
what you can do is:
boundStatement.setString(id, rowkey);
boundStatement.setBytesUnsafe(columnname, ByteBuffer.wrap(new
byte[0]));
boundStatement.setBytes(columnvalue, ByteBuffer.wrap(value));
In other words, the shorthand BoundStatement.bind() won't let you insert
an empty value for types
that don't naturally have an empty value (like int; keep in mind that an
empty value is not the same
than null). But you can circumvent that using setBytesUnsafe if you
really want.
Long story short, my advice would be to avoid using empty values for type
that don't naturally have
one (anything else than text and blob really). If you do, that's going to
be painful (but possible) to
work with, at least with the java driver (but for good reasons, java just
doesn't have a good to
represent an empty int value (again, you can have a null Integer but
that's different)).
--
Sylvain
Thanks a ton,
Vikas Goyal
On Tue, Sep 24, 2013 at 9:05 PM, Sylvain Lebresne sylv...@datastax.com
mailto:sylv...@datastax.com wrote:
However,we tried missing the value but it didn't work :(
Right, because not providing a value is akin to having a null value (in
the CQL3 sense of the term, which is different from what Dean asked about)
and null values are not allowed for primary key columns.
You could however insert an *empty* value if you wanted, which in you
case is just inserting an empty string since colname is a string. Thrift
doesn't allow more or less in that case.
--
Sylvain
So our code is like below where we are using 3 values if colname is not
null..else 2 values..
if (key != null) {
PreparedStatement statement = session.prepare(INSERT
INTO keys.StringIndice (id, colname, colvalue) VALUES (?, ?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey
Re: is this correct, thrift unportable to CQL3Š.
Nulls should definitely stay null (that's an old DB debate), but if this
is a generic case, we might consider adding an emptyValue() helper method.
Would that be possible Sylvain?
As said previously, debating this is outside the scope of this mailing
list, but to make it short, using empty values for types that don't
naturally support them like Integer is going to be painful (inserting is
one thing, handling them on the read side is another) and confusing no
matter what. So you should avoid it in the first place (and there is *tons*
of way to do that) and consequently adding an helper to do something you
should avoid is a bad idea.
--
Sylvain
--
Sylvain
Ie. This sounds like this solution would be perfect if we can get rid of
the exception piece.
Thanks much!!!
Dean
From: Sylvain Lebresne sylv...@datastax.commailto:sylv...@datastax.com
Reply-To: user@cassandra.apache.orgmailto:user@cassandra.apache.org
user@cassandra.apache.orgmailto:user@cassandra.apache.org
Date: Tuesday, September 24, 2013 10:58 AM
To: user@cassandra.apache.orgmailto:user@cassandra.apache.org
user@cassandra.apache.orgmailto:user@cassandra.apache.org
Subject: Re: is this correct, thrift unportable to CQL3Š.
On Tue, Sep 24, 2013 at 6:17 PM, Vikas Goyal vi...@easility.commailto:
vi...@easility.com wrote:
Ok. Great. It works for String and Decimal/Float but not for integer
data type..
i.e,, if I am passing to the composite key column which is either
text or float, it works..
session.execute(boundStatement.bind(rowkey, , ByteBuffer.wrap(value)));
But not working with bigint, int or varint..and getting following
exception;
Exception:Invalid type for value 1 of CQL type varint, expecting class
java.math.BigInteger but class java.lang.String provided
..I am exploring more though..
We're getting into details of the java driver at this point. For int,
what you can do is:
boundStatement.setString(id, rowkey);
boundStatement.setBytesUnsafe(columnname, ByteBuffer.wrap(new
byte[0]));
boundStatement.setBytes(columnvalue, ByteBuffer.wrap(value));
In other words, the shorthand BoundStatement.bind() won't let you insert
an empty value for types
that don't naturally have an empty value (like int; keep in mind that an
empty value is not the same
than null). But you can circumvent that using setBytesUnsafe if you
really want.
Long story short, my advice would be to avoid using empty values for
type that don't naturally have
one (anything else than text and blob really). If you do, that's going
to be painful (but possible) to
work with, at least with the java driver (but for good reasons, java
just doesn't have a good to
represent an empty int value (again, you can have a null Integer but
that's different)).
--
Sylvain
Thanks a ton,
Vikas Goyal
On Tue, Sep 24, 2013 at 9:05 PM, Sylvain Lebresne sylv...@datastax.com
mailto:sylv...@datastax.com wrote:
However,we tried missing the value but it didn't work :(
Right, because not providing a value is akin to having a null value (in
the CQL3 sense of the term, which is different from what Dean asked about)
and null values are not allowed for primary key columns.
You could however insert an *empty* value if you wanted, which in you
case is just inserting an empty string since colname is a string. Thrift
doesn't allow more or less in that case.
--
Sylvain
So our code is like below where we are using 3 values if colname is not
null..else 2 values..
if (key != null) {
PreparedStatement statement = session.prepare(INSERT
INTO keys.StringIndice (id, colname, colvalue) VALUES (?, ?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), key, ByteBuffer.wrap(value)));
} else {
PreparedStatement statement = session.prepare(INSERT
INTO + keys + . + table + (id, colvalue) VALUES (?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), ByteBuffer.wrap(value)));
}
And, I did that and getting this exception:
Exception:Missing PRIMARY KEY part colname since colvalue is set
And just FYI. Our Column Family definition is below:
CREATE TABLE keys.StringIndice (id text,
colname text,
colvalue blob,
PRIMARY KEY (id,colname, colvalue)) WITH COMPACT STORAGE)
Thanks again,
Vikas Goyal
On Tue, Sep 24, 2013 at 7:02 PM, Sylvain Lebresne sylv...@datastax.com
mailto:sylv...@datastax.com wrote:
Short answer: not, this is not correct.
Longer answer: what you call null is actually an empty value (which is
*not* the same thing, unless you consider an empty string is the same thing
than a null string). As it happens, C* always an empty value as a valid
value for any type and that's true
Re: is this correct, thrift unportable to CQL3Š.
Thanks Sylvain,
However,we tried missing the value but it didn't work :(
So our code is like below where we are using 3 values if colname is not
null..else 2 values..
if (key != null) {
PreparedStatement statement = session.prepare(INSERT INTO
keys.StringIndice (id, colname, colvalue) VALUES (?, ?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), key, ByteBuffer.wrap(value)));
} else {
PreparedStatement statement = session.prepare(INSERT INTO
+ keys + . + table + (id, colvalue) VALUES (?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), ByteBuffer.wrap(value)));
}
And, I did that and getting this exception:
Exception:Missing PRIMARY KEY part colname since colvalue is set
And just FYI. Our Column Family definition is below:
CREATE TABLE keys.StringIndice (id text,
colname text,
colvalue blob,
PRIMARY KEY (id,colname, colvalue)) WITH COMPACT STORAGE)
Thanks again,
Vikas Goyal
On Tue, Sep 24, 2013 at 7:02 PM, Sylvain Lebresne sylv...@datastax.comwrote:
Short answer: not, this is not correct.
Longer answer: what you call null is actually an empty value (which is
*not* the same thing, unless you consider an empty string is the same thing
than a null string). As it happens, C* always an empty value as a valid
value for any type and that's true of both thrift and CQL3. What is true is
that CQL3 discourage the use of empty values for type for which it doesn't
particularly make sense (integers typically) by not having a particular
easy to use syntax to input them. But that's supported nonetheless. If you
use a prepared statement for instance (where you send values already
serialized), nothing will prevent you from sending an empty value. Even if
you don't want to use a prepared statement, CQL3 has conversion functions (
http://cassandra.apache.org/doc/cql3/CQL.html#blobFun) that allows to do
it (for instance, blobAsInt(0x) will be an empty int value).
--
Sylvain
On Tue, Sep 24, 2013 at 2:36 PM, Hiller, Dean dean.hil...@nrel.govwrote:
Many applications in thrift use the wide row with composite column name
and as an example, let's say golf score for instance and we end up with
golf score : pk like so
null : pk56
null : pk45
89 : pk90
89: pk87
90: pk101
95: pk17
Notice that there are some who do not have a golf score(zero would not
quite make sense and would be interpreted as a golf score). I am hearing
from this post if they are correct that this is not portable to CQL3??? Is
this true?
http://stackoverflow.com/questions/18963248/how-can-i-have-null-column-value-for-a-composite-key-column-in-cql3
(This sounds like a major deficit to me as the wide row now can only be
used where actual values exist?). Is it possible to port this pattern
to CQL3?
Thanks,
Dean
Re: is this correct, thrift unportable to CQL3Š.
However,we tried missing the value but it didn't work :(
Right, because not providing a value is akin to having a null value (in the
CQL3 sense of the term, which is different from what Dean asked about) and
null values are not allowed for primary key columns.
You could however insert an *empty* value if you wanted, which in you case
is just inserting an empty string since colname is a string. Thrift doesn't
allow more or less in that case.
--
Sylvain
So our code is like below where we are using 3 values if colname is not
null..else 2 values..
if (key != null) {
PreparedStatement statement = session.prepare(INSERT INTO
keys.StringIndice (id, colname, colvalue) VALUES (?, ?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), key, ByteBuffer.wrap(value)));
} else {
PreparedStatement statement = session.prepare(INSERT INTO
+ keys + . + table + (id, colvalue) VALUES (?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), ByteBuffer.wrap(value)));
}
And, I did that and getting this exception:
Exception:Missing PRIMARY KEY part colname since colvalue is set
And just FYI. Our Column Family definition is below:
CREATE TABLE keys.StringIndice (id text,
colname text,
colvalue blob,
PRIMARY KEY (id,colname, colvalue)) WITH COMPACT STORAGE)
Thanks again,
Vikas Goyal
On Tue, Sep 24, 2013 at 7:02 PM, Sylvain Lebresne sylv...@datastax.comwrote:
Short answer: not, this is not correct.
Longer answer: what you call null is actually an empty value (which is
*not* the same thing, unless you consider an empty string is the same thing
than a null string). As it happens, C* always an empty value as a valid
value for any type and that's true of both thrift and CQL3. What is true is
that CQL3 discourage the use of empty values for type for which it doesn't
particularly make sense (integers typically) by not having a particular
easy to use syntax to input them. But that's supported nonetheless. If you
use a prepared statement for instance (where you send values already
serialized), nothing will prevent you from sending an empty value. Even if
you don't want to use a prepared statement, CQL3 has conversion functions (
http://cassandra.apache.org/doc/cql3/CQL.html#blobFun) that allows to do
it (for instance, blobAsInt(0x) will be an empty int value).
--
Sylvain
On Tue, Sep 24, 2013 at 2:36 PM, Hiller, Dean dean.hil...@nrel.govwrote:
Many applications in thrift use the wide row with composite column name
and as an example, let's say golf score for instance and we end up with
golf score : pk like so
null : pk56
null : pk45
89 : pk90
89: pk87
90: pk101
95: pk17
Notice that there are some who do not have a golf score(zero would not
quite make sense and would be interpreted as a golf score). I am hearing
from this post if they are correct that this is not portable to CQL3??? Is
this true?
http://stackoverflow.com/questions/18963248/how-can-i-have-null-column-value-for-a-composite-key-column-in-cql3
(This sounds like a major deficit to me as the wide row now can only be
used where actual values exist?). Is it possible to port this pattern
to CQL3?
Thanks,
Dean
Re: is this correct, thrift unportable to CQL3Š.
Ok. Great. It works for String and Decimal/Float but not for integer data
type..
i.e,, if I am passing to the composite key column which is either text
or float, it works..
session.execute(boundStatement.bind(rowkey, , ByteBuffer.wrap(value)));
But not working with bigint, int or varint..and getting following exception;
Exception:Invalid type for value 1 of CQL type varint, expecting class
java.math.BigInteger but class java.lang.String provided
..I am exploring more though..
Thanks a ton,
Vikas Goyal
On Tue, Sep 24, 2013 at 9:05 PM, Sylvain Lebresne sylv...@datastax.comwrote:
However,we tried missing the value but it didn't work :(
Right, because not providing a value is akin to having a null value (in
the CQL3 sense of the term, which is different from what Dean asked about)
and null values are not allowed for primary key columns.
You could however insert an *empty* value if you wanted, which in you case
is just inserting an empty string since colname is a string. Thrift doesn't
allow more or less in that case.
--
Sylvain
So our code is like below where we are using 3 values if colname is not
null..else 2 values..
if (key != null) {
PreparedStatement statement = session.prepare(INSERT
INTO keys.StringIndice (id, colname, colvalue) VALUES (?, ?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), key, ByteBuffer.wrap(value)));
} else {
PreparedStatement statement = session.prepare(INSERT
INTO + keys + . + table + (id, colvalue) VALUES (?, ?));
BoundStatement boundStatement = new
BoundStatement(statement);
session.execute(boundStatement.bind(StandardConverters.convertFromBytes(String.class,
rowKey), ByteBuffer.wrap(value)));
}
And, I did that and getting this exception:
Exception:Missing PRIMARY KEY part colname since colvalue is set
And just FYI. Our Column Family definition is below:
CREATE TABLE keys.StringIndice (id text,
colname text,
colvalue blob,
PRIMARY KEY (id,colname, colvalue)) WITH COMPACT STORAGE)
Thanks again,
Vikas Goyal
On Tue, Sep 24, 2013 at 7:02 PM, Sylvain Lebresne
sylv...@datastax.comwrote:
Short answer: not, this is not correct.
Longer answer: what you call null is actually an empty value (which is
*not* the same thing, unless you consider an empty string is the same thing
than a null string). As it happens, C* always an empty value as a valid
value for any type and that's true of both thrift and CQL3. What is true is
that CQL3 discourage the use of empty values for type for which it doesn't
particularly make sense (integers typically) by not having a particular
easy to use syntax to input them. But that's supported nonetheless. If you
use a prepared statement for instance (where you send values already
serialized), nothing will prevent you from sending an empty value. Even if
you don't want to use a prepared statement, CQL3 has conversion functions (
http://cassandra.apache.org/doc/cql3/CQL.html#blobFun) that allows to
do it (for instance, blobAsInt(0x) will be an empty int value).
--
Sylvain
On Tue, Sep 24, 2013 at 2:36 PM, Hiller, Dean dean.hil...@nrel.govwrote:
Many applications in thrift use the wide row with composite column name
and as an example, let's say golf score for instance and we end up with
golf score : pk like so
null : pk56
null : pk45
89 : pk90
89: pk87
90: pk101
95: pk17
Notice that there are some who do not have a golf score(zero would not
quite make sense and would be interpreted as a golf score). I am hearing
from this post if they are correct that this is not portable to CQL3??? Is
this true?
http://stackoverflow.com/questions/18963248/how-can-i-have-null-column-value-for-a-composite-key-column-in-cql3
(This sounds like a major deficit to me as the wide row now can only be
used where actual values exist?). Is it possible to port this pattern
to CQL3?
Thanks,
Dean
