If I were retrieving the data I wanted from a plain sql query, the following would suffice:
select * from stvterm where stvterm_code > TT_STUDENT.STU_GENERAL.F_Get_Current_term()
I have a grails domain set up correctly for this table, and I can run the following code successfully:
def a = SaturnStvterm.findAll("from SaturnStvterm as s where id > 201797") as JSON
a.render(response)
return false
In other words, I can hardcode in the results from the Oracle function and have the HQL run correctly, but it chokes any way that I can figure to try it with the function. I have read through some of the documentation on Hibernate about using procs and functions, but I'm having trouble making much sense of it. Can anyone give me a hint as to the proper way to handle this?
Also, since I think it is probably relevant, there aren't any synonyms in place that would allow the function to be called without qualifying it as schema.package.function(). I'm sure that'll make things more difficult. This is all for Grails 1.3.7, though I could use a later version if needed.
To call a function in HQL, the SQL dialect must be aware of it. You can add your function at runtime in BootStrap.groovy like this:
import org.hibernate.dialect.function.SQLFunctionTemplate
import org.hibernate.Hibernate
def dialect = applicationContext.sessionFactory.dialect
def getCurrentTerm = new SQLFunctionTemplate(Hibernate.INTEGER, "TT_STUDENT.STU_GENERAL.F_Get_Current_term()")
dialect.registerFunction('F_Get_Current_term', getCurrentTerm)
Once registered, you should be able to call the function in your queries:
def a = SaturnStvterm.findAll("from SaturnStvterm as s where id > TT_STUDENT.STU_GENERAL.F_Get_Current_term()")
Related
The below query i want to add allowDiskUse true. I am able to add allowDiskUsage to aggregation query but not able to find a solution for find method
Query query = new Query().with(pageable).addCriteria(criteria).collation(collation);
mongoOperations.find(query, RuntimeApplication.class, RUNTIME_APP);
I want to know is that possible to add allowDiskUsage to find method or i need to change query to aggregation.
i just found in below query from internet. but i am not getting how to convert it into spring boot
db.collection.find(<match>).sort(<sort>).allowDiskUse()
What kind of spring-data version are you using? You should be able to add allowDiskUse to the Query object just like this:
val query = Query()
.with(Pageable.ofSize(1))
.addCriteria(Criteria())
.allowDiskUse(true)
And then afterwards use the query with find for instance with mongoTemplate.
Here is the documentation: https://javadoc.io/doc/org.springframework.data/spring-data-mongodb/latest/org/springframework/data/mongodb/core/query/Query.html
I'm looking for an implementation to run text query ex: "g.V().limit(1).toList()" while using the PatitionStrategy in Apache TinkerPop.
I'm attempting to build a REST interface to run queries on selected graph paritions only. I know how to run a raw query using Client, but I'm looking for an implementation where I can create a multi-tenant graph (https://tinkerpop.apache.org/docs/current/reference/#partitionstrategy) and query only selected tenants using raw text query instead of a GLV. Im able to query only selected partitions using pythongremlin, but there is no reference implementation I could find to run a text query on a tenant.
Here is tenant query implementation
connection = DriverRemoteConnection('ws://megamind-ws:8182/gremlin', 'g')
g = traversal().withRemote(connection)
partition = PartitionStrategy(partition_key="partition_key",
write_partition="tenant_a",
read_partitions=["tenant_a"])
partitioned_g = g.withStrategies(partition)
x = partitioned_g.V.limit(1).next() <---- query on partition only
Here is how I execute raw query on entire graph, but Im looking for implementation to run text based queries on only selected partitions.
from gremlin_python.driver import client
client = client.Client('ws://megamind-ws:8182/gremlin', 'g')
results = client.submitAsync("g.V().limit(1).toList()").result().one() <-- runs on entire graph.
print(results)
client.close()
Any suggestions appreciated? TIA
It depends on how the backend store handles text mode queries, but for the query itself, essentially you just need to use the Groovy/Java style formulation. This will work with GremlinServer and Amazon Neptune. For other backends you will need to make sure that this syntax is supported. So from Python you would use something like:
client.submit('
g.withStrategies(new PartitionStrategy(partitionKey: "_partition",
writePartition: "b",
readPartitions: ["b"])).V().count()')
I have something like this, using Akka, Alpakka + Slick
Slick
.source(
sql"""select #${onlyTheseColumns.mkString(",")} from #${dbSource.table}"""
.as[Map[String, String]]
.withStatementParameters(rsType = ResultSetType.ForwardOnly, rsConcurrency = ResultSetConcurrency.ReadOnly, fetchSize = batchSize)
.transactionally
).map( doSomething )...
I want to update this plain sql query with skipping the first N-th element.
But that is very DB specific.
Is is possible to get the pagination bit generated by Slick? [like for type-safe queries one just do a drop, filter, take?]
ps: I don't have the Schema, so I cannot go the type-safe way, just want all tables as Map, filter, drop etc on them.
ps2: at akka level, the flow.drop works, but it's not optimal/slow, coz it still consumes the rows.
Cheers
Since you are using the plain SQL, you have to provide a workable SQL in code snippet. Plain SQL may not type-safe, but agile.
BTW, the most optimal way is to skip N-th element by Database, such as limit in mysql.
depending on your database engine, you could use something like
val page = 1
val pageSize = 10
val query = sql"""
select #${onlyTheseColumns.mkString(",")}
from #${dbSource.table}
limit #${pageSize + 1}
offset #${pageSize * (page - 1)}
"""
the pageSize+1 part tells you whether the next page exists
I want to update this plain sql query with skipping the first N-th element. But that is very DB specific.
As you're concerned about changing the SQL for different databases, I suggest you abstract away that part of the SQL and decide what to do based on the Slick profile being used.
If you are working with multiple database product, you've probably already abstracted away from any specific profile, perhaps using JdbcProfile. In that case you could place your "skip N elements" helper in a class and use the active slickProfile to decide on the SQL to use. (As an alternative you could of course check via some other means, such as an environment value you set).
In practice that could be something like this:
case class Paginate(profile: slick.jdbc.JdbcProfile) {
// Return the correct LIMIT/OFFSET SQL for the current Slick profile
def page(size: Int, firstRow: Int): String =
if (profile.isInstanceOf[slick.jdbc.H2Profile]) {
s"LIMIT $size OFFSET $firstRow"
} else if (profile.isInstanceOf[slick.jdbc.MySQLProfile]) {
s"LIMIT $firstRow, $size"
} else {
// And so on... or a default
// Danger: I've no idea if the above SQL is correct - it's just placeholder
???
}
}
Which you could use as:
// Import your profile
import slick.jdbc.H2Profile.api._
val paginate = Paginate(slickProfile)
val action: DBIO[Seq[Int]] =
sql""" SELECT cols FROM table #${paginate.page(100, 10)}""".as[Int]
In this way, you get to isolate (and control) RDBMS-specific SQL in one place.
To make the helper more usable, and as slickProfile is implicit, you could instead write:
def page(size: Int, firstRow: Int)(implicit profile: slick.jdbc.JdbcProfile) =
// Logic for deciding on SQL goes here
I feel obliged to comment that using a splice (#$) in plain SQL opens you to SQL injection attacks if any of the values are provided by a user.
I'm currently trying to create an Endeca query using the Java API for a URLENEQuery. The current query is:
collection()/record[CONTACT_ID = "xxxxx" and SALES_OFFICE = "yyyy"]
I need it to be:
collection()/record[(CONTACT_ID = "xxxxx" or CONTACT_ID = "zzzzz") and
SALES_OFFICE = "yyyy"]
Currently this is being done with an ERecSearchList with CONTACT_ID and the string I'm trying to match in an ERecSearch object, but I'm having difficulty figuring out how to get the UrlENEQuery to generate the or in the correct fashion as I have above. Does anyone know how I can do this?
One of us is confused on multiple levels:
Let me try to explain why I am confused:
If Contact_ID and Sales_Office are different dimensions, where Contact_ID is a multi-or dimension, then you don't need to use EQL (the xpath like language) to do anything. Just select the appropriate dimension values and your navigation state will reflect the query you are trying to build with XPATH. IE CONTACT_IDs "ORed together" with SALES_OFFICE "ANDed".
If you do have to use EQL, then the only way to modify it (provided that you have to modify it from the returned results) is via string manipulation.
ERecSearchList gives you ability to use "Search Within" functionality which functions completely different from the EQL filtering, though you can achieve similar results by using tricks like searching only specified field (which would be separate from the generic search interface") I am still not sure what's the connection between ERecSearchList and the EQL expression above?
Having expressed my confusion, I think what you need to do is to use String manipulation to dynamically build the EQL expression and add it to the Query.
A code example of what you are doing would be extremely helpful as well.
With Django it is possible to find models using the filter method with keyword-arguments like so:
MyModel.objects.filter(serialNo_gt=10)
giving all models with a serial number greater than 10.
Is it possibly to use a similar query language with sql-alchemy? I know that one can write something like MyModel.seriealNO < 10, but with that the code that uses this construct need to import MyModel and I want to create the keywords/query parameters externally without importing MyModel (for a facade-pattern).
the concept of "<attributename>_<operatorname>=<value>" is not built in to SQLAlchemy's Query, however the effect is very easy to reproduce. Here's a quick example done by the author of Flask: https://github.com/mitsuhiko/sqlalchemy-django-query/blob/master/sqlalchemy_django_query.py