Error querying table schema: Undefined name key_aliases in selection clause

[maticmeznar]

I'm new to Cassandra (version 2.2.1) and I've been using http://relops.com/cqlc/start/ to get me started with accessing it from Go. I'm able to create the keyspace using the linked schema.cql, but when I run the cqlc command in the example, I get the error: " Error querying table schema: Undefined name key_aliases in selection clause".

What is wrong? Why isn't it working?

[nsd20463]

I'm not the cqlc author, but we happened to find this same error the other day. It comes from the getTableMetaData() function of the gocql package. cqlc uses this function to read the schema. Cassandra 2.2 removed key_aliases (and column_aliases and value_aliases) from this table. So the function breaks.

The quick fix is to use Cassandra 2.1.

[maticmeznar]

@nsd20463 Thank you! You just saved me a lot of time. I hope support for Cassandra 2.2 is added soon. What does the cqlc author say about that?

[0x6e6562]

@maticmeznar I don't see why this shouldn't be added, considering that 2.2.0 is now one of the supported versions in gocql. I can let you know when that happens, or if you want to speed the process up a bit, feel free to raise a PR.

[0x6e6562]

I've had a closer look at this and have tried a few things out. It turns out that setting ProtoVersion on the gocql cluster config to 4 will avoid the issue with key_aliases. However, there are other few compatibility issues that need to get cleaned up to declare this to be ready for 2.2.+

[maticmeznar]

@0x6e6562 Thank you for looking into this. I've currently resorted to using plain gocql as I can't find a way to set per query consistency level when using cqlc. I presume it's not supported.

[0x6e6562]

@maticmeznar cqlc tries not to hide any of the gocql API from the app, but there may be some use cases where it doesn't achieve this - in which case we would need to revise the cqlc API to make this happen.

However, I'm wondering whether this part of the user guide can give you an idea of how to access the *gocql.Query object to set the per-query consistency level?

[0x6e6562]

@maticmeznar @nsd20463 I've just merged #29 which now runs the test suite against 2.1.9 and 2.2.1 (and in doing so, deprecating support for 2.0.x). The functional change in the cqlc compiler is that it now looks for the native version of the server from which it is trying to harvest the schema. If it detects that the protocol version is above 3 (i.e. as in the case of 2.2.x), cqlc will re-connect to the server using the upgraded protocol version. This avoids the key_aliases issue in 2.2.x. Let me know if this works for you.

[bobu]

I've just verified that this fixes support for Cassandra 2.2 (in my case, I'm running 2.2.3).

[0x6e6562]

@bobu Many thanks for verifying this fix :-)

@maticmeznar @nsd20463 I'll still leave this issue open for a while to give you more time to try this out.