I'm trying to run my service with Micronaut and Cassandra (currently version 3.11.10) and store a column that is a set of tuples into Cassandra.
example code:
QueryBuilder
.insertInto(table)
.value("column", QueryBuilder.literal(items.map { it.toTuple() }.toSet())))
The toTuple() method is just an extension method that transfer the items into Term objects
When I'm doing so I'm receiving the following error:
Internal Server Error: Could not inline literal of type java.util.Collections$SingletonSet. This happens because the driver doesn't know how to map it to a CQL type. Try passing a TypeCodec or CodecRegistry to literal().
I've checked online in multiple sources but couldn't find a simple way to store a set of tuples into the database without implementing my custom TypeCodec. As I'm sure that I'm not the first person to have this issue, I'm probably doing something completely wrong, however I couldn't find any documentation regarding to what is the correct way of doing this.
Related
I use jooq to generate objects against a local database, but when running "for real" later in production the actual databases will have different names. To remedy this I use the <outputSchemaToDefault>true</outputSchemaToDefault> config option (maven).
At the same time, we have multiple databases (schemas), and are using a connection pool to the server like "jdbc:mysql://localhost:3306/" (without specifying a database here).
How do I tell jooq which database to use when running queries?
I have tried all config I can think of:
new Settings()
.withRenderSchema(true) // true/false seems to make no difference.
.withRenderCatalog(true) // true/false seems to make no difference.
.withRenderMapping(new RenderMapping()
.withDefaultSchema("my_database") // Seems to have no effect.
// The above 3 configs always give me an error saying "no database selected".
// Adding this gives me 'my_database.my_table' does not exist - while it actually does.
.withSchemata(new MappedSchema()
.withInputExpression(Pattern.compile(".*"))
.withOutput("my_database")
));
I have also tried using a database/schema name, as in not configuring outputSchemaToDefault. But then, adding the MappedSchema code above, but that gives me errors with "'my_databasemy_database.my_table' does not exist", which is correct. I have no clue why that code gives me the database/schema name twice?
Edit:
When jooq tells me that the db.table does not exist, if I put a break point in a good place and get the sql from jooq and run exactly that against my database it does work. But jooq fails to run it.
Also, I'm using version 3.15.3 of jooq.
I solved it. Instead of using .withInputExpression(Pattern.compile(".*")), it seems to work with .withInput("").
I'm still not sure why it works, or if this is the "correct" way of solving it. But at least it is a way forward.
No clue why using the pattern, I got the name twice though. But that one I'll leave alone.
I am using Spark-Solr connector 3.4.0 with Solr cloud version 7.6.0 in a Spark 2.2.1 Cluster . We have an existing Solr collection with a predefined schema for it. Most of the fields have the stored parameter set to true, but there are certain fields where we explicitly set stored=false. When we try to push data to Solr using the spark-solr connector, we get the following error-
org.apache.solr.api.ApiBag$ExceptionWithErrObject: error processing commands, errors: [{add-field={name=taxonomy, indexed=true, multiValued=true, docValues=true, stored=true, type=string}, errorMessages=[Field 'item_id_channel' already exists.
]}],
at org.apache.solr.handler.SchemaHandler.handleRequestBody(SchemaHandler.java:92)
at org.apache.solr.handler.RequestHandlerBase.handleRequest(RequestHandlerBase.java:199)
at org.apache.solr.core.SolrCore.execute(SolrCore.java:2541)
at org.apache.solr.servlet.HttpSolrCall.execute(HttpSolrCall.java:709)
at org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:515)
at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:377)
at org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:323)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1634)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533)
The error says the item_id_channel already exists, but this error is only raised for fields for which we have defined stored=false (in the Solr schema). I get that the connector wishes to create the schema again for some reason, but it sets the stored parameter to true which clashes with the predefined schema definition on Solr for this field.
My question is - Is there a way to tell the connector (probably through some option?) that we want the stored to be set to true for certain fields? And probably a generic way to define other solr parameters for the fields?
We found the issue that was causing the error. There was a bug in older versions of spark-solr connector, because of which the connector was trying to add existing fields to the solr schema in case the value of stored was true. This was fixed in 3.5.5 release. Hence, once we upgraded our connector to version 3.5.14, the ingestion stared working without any errors.
I am building a REST API which connects to a NEO4J instance. I am using the koa-neo4j library as the basis (https://github.com/assister-ai/koa-neo4j-starter-kit). I am a beginner at all these technologies but thanks to some help from this forum I have the basic functionality working. For example the below code allows me to create a new node with the label "metric" and set the name and dateAdded propertis.
URL:
/metric?metricName=Test&dateAdded=2/21/2017
index.js
app.defineAPI({
method: 'POST',
route: '/api/v1/imm/metric',
cypherQueryFile: './src/api/v1/imm/metric/createMetric.cyp'
});
createMetric.cyp"
CREATE (n:metric {
name: $metricName,
dateAdded: $dateAdded
})
return ID(n) as id
However, I am struggling to know how I can approach more complicated examples. How can I handle situations when I don't know how many properties will be added when creating a new node beforehand or when I want to create multiple nodes in a single post statement. Ideally I would like to be able to pass something like JSON as part of the POST which would contain all of the nodes, labels and properties that I want to create. Is something like this possible? I tried using the below Cypher query and passing a JSON string in the POST body but it didn't work.
UNWIND $props AS properties
CREATE (n:metric)
SET n = properties
RETURN n
Would I be better off switching tothe Neo4j Rest API instead of the BOLT protocol and the KOA-NEO4J framework. From my research I thought it was better to use BOLT but I want to have a Rest API as the middle layer between my front and back end so I am willing to change over if this will be easier in the longer term.
Thanks for the help!
Your Cypher syntax is bad in a couple of ways.
UNWIND only accepts a collection as its argument, not a string.
SET n = properties is only legal if properties is a map, not a string.
This query should work for creating a single node (assuming that $props is a map containing all the properties you want to store with the newly created node):
CREATE (n:metric $props)
RETURN n
If you want to create multiple nodes, then this query (essentially the same as yours) should work (but only if $prop_collection is a collection of maps):
UNWIND $prop_collection AS props
CREATE (n:metric)
SET n = props
RETURN n
I too have faced difficulties when trying to pass complex types as arguments to neo4j, this has to do with type conversions between js and cypher over bolt and there is not much one could do except for filing an issue in the official neo4j JavaScript driver repo. koa-neo4j uses the official driver under the hood.
One way to go about such scenarios in koa-neo4j is using JavaScript to manipulate the arguments before sending to Cypher:
https://github.com/assister-ai/koa-neo4j#preprocess-lifecycle
Also possible to further manipulate the results of a Cypher query using postProcess lifecycle hook:
https://github.com/assister-ai/koa-neo4j#postprocess-lifecycle
What is the equivalent of:
INSERT INTO table (myColumn) VALUES (now())
using the Cassandra object-mapping api?
The #Computed annotation doesnt look like it would work unfortunately.
You can also set the value of your object to a type1 uuid. The jre doesnt have standard function for it but you can use the java driver util, JUG, cassandra-all or even write one yourself. This would be a little different because your setting the time as the time of creation as opposed to coordinator setting time of when it receives the request but with ORM's abstractions you tend to lose some control.
Alternatively there is nothing preventing you from issuing CQL statements while still using the object mapping api. Maybe even adding a query to a method on your object to do it ie:
#Query("UPDATE table SET myColumn = now() WHERE ....")
public ResultSet setNow()
I am using titan 0.4.2 with cassandra 2.0.7 as the storage back end. I have used rexter-server 2.4.0 to insert vertex in the titan. However while i am trying to update a vertex property using rexter client I am getting null pointer exception.
RexsterClient client = RexsterClientFactory.open("localhost", "titangraph");
client.execute("g.getVertex(8).setProperty('name','William')");
The above code is throwing null pointer exception. However the script g.getVertex(8).setProperty('name','William') runs perfectly fine in the gremlin console
How can i update titan vertex property using rexster rexpro?
I will assume that you are saying the NullPointerException (NPE) is coming from the script executed on the server-side. In other words, the problem is a result of running:
g.getVertex(8).setProperty('name','William')
and not something in the client instantiation or related to other client side code beyond the script itself.
With that assumption in mind, I could not recreate your error. The execute method does return a list with a single null within it but I don't think you're referring to that as your problem given the assumption. So, there's really only two things that could be wrong that I can think of:
The vertex returned by g.v(8) does not exist and it returns null
g is null
To verify, just execute g.v(8). If it returns null then item one above is the issue. If you still get an NPE then item two above is the problem. If item two is the problem then the name of the graph you are referencing, titangraph, is either not right or there is a bug in Rexster's handling of that binding. To figure that out, execute this instead:
g = rexster.getGraph('titangraph')
g.v(8)
If you still have a NPE then I'd have to say that you need to check your rexster.xml more carefully regarding your configuration. If it works, then you should likely report a bug in Rexster.