I'm trying to call a Postgres function with Criteria but it's not working. I need to use the LIKE clause in a UUID field, so I need to convert into VARCHAR first.
The result I need:
SELECT * FROM my_table WHERE cast(uuid as varchar(36)) like '%1234%';
What I'm doing in Criteria:
final Path<UUID> uuidField = from.get("uuid");
var cast = cb.function("cast", String.class, uuidField, cb.literal("as varchar(36)"));
cb.like(cast, String.format("%%%s%%", stringValue));
The query which is being generated:
HQL: select generatedAlias0 from com.MyTable as generatedAlias0 where function('cast', generatedAlias0.uuid, 'as varchar(36)') like '%1234%' order by generatedAlias0.name asc
Error:
2022-08-08 18:38:48,549 WARN [io.ver.cor.imp.BlockedThreadChecker] (vertx-blocked-thread-checker) Thread Thread[vert.x-eventloop-thread-9,5,main] has been blocked for 2393 ms, time limit is 2000 ms: io.vertx.core.VertxException: Thread blocked
at antlr.ASTFactory.make(ASTFactory.java:342)
at antlr.ASTFactory.make(ASTFactory.java:352)
at org.hibernate.hql.internal.antlr.HqlBaseParser.jpaFunctionSyntax(HqlBaseParser.java:4633)
at org.hibernate.hql.internal.antlr.HqlBaseParser.primaryExpression(HqlBaseParser.java:1075)
The log is not so clear (I'm using Quarkus + Hibernate Reactive), but I suspect it crashed in database because the function('cast', generatedAlias0.uuid, 'as varchar(36)').
I think it should be something like: function('cast', generatedAlias0.uuid, as varchar(36)) (without quotes). But I don't know how to achieve this result to test my theory.
How can I call this CAST function?
After investigating some possible solutions (I'm avoiding to create custom database routines) I found something interesting in a answer from another question:
Currently JPA does not have APIs for replace() and cast(string as numeric). But you can use CriteriaBuilder.function(...) to create database native functions if database portability is not critical.
Source: JPA criteria builder: how to replace and cast a string to numeric in order-by?
I don't know if this is documented is some place, but assuming that there is no way to call CAST(x AS y) using Criteria, I tried a workaround to force the UUID to VARCHAR cast without using the probably unsupported CAST function.
I tested this direct SQL query to database:
SELECT * FROM my_table WHERE concat(uuid, '') like '%123%';
And it works. This CONCAT forces the cast to VARCHAR and the LIKE function does his job. Knowing this, I did:
final Path<UUID> uuidField = from.get("uuid");
var cast = cb.function("concat", String.class, uuidField, cb.literal(""));
cb.like(cast, String.format("%%%s%%", stringValue));
Worked perfectly. I hope this help someone else.
As #HaroldH said, it's a weird requirement, but happened in my project.
Related
I have a query that returns a Postgres array of UUIDs:
SELECT e.id, e.date,
ARRAY
(
SELECT cs.api_id FROM event_condition_set ecs
JOIN condition_set cs on cs.id = ecs.condition_set_id
WHERE ecs.event_id = e.id
) AS condition_set_ids,
...
And then create and run this query as a native query: Query query = entityManager.createNativeQuery(queryString);
Since Hibernate can normally not deal with these Postgres arrays, I use Vlad's Hibernate Types library.
However, currently I need to register this UUIDArrayType globally in my application:
public class PostgreSQL95CustomDialect extends PostgreSQL95Dialect {
public PostgreSQL95CustomDialect() {
super();
this.registerHibernateType(Types.ARRAY, UUIDArrayType.class.getName());
}
}
Aside from the fact this is a bit ugly, it also leaves no room for other types of arrays.
(Note I also tried registering a generic ListArrayType but this throws a NullPointerException during execution of the query.)
I have also tried registering it as a scalar type:
query.unwrap(org.hibernate.query.NativeQuery.class)
.addScalar("condition_set_ids", UUIDArrayType.INSTANCE);
But this makes the entire query only return a single UUID, which is very strange and seems bugged.
Is there a way to ONLY use this UUIDArrayType specifically in this query?
(Please don't suggest using array_agg because the performance is terrible for this case)
you can call native queries using custom Hibernate types as follows:
String myJsonbData = ...;
String[] myStringArr = ...;
final String queryStr = "select your_function(?, ?, ...)"; // ? for each param
entityManager
.createNativeQuery(queryStr)
.setParameter(1, new TypedParameterValue(JsonBinaryType.INSTANCE, myJsonbData))
.setParameter(2, new TypedParameterValue(StringArrayType.INSTANCE, myStringArr));
This is just an example, but as a rule of thumb, you need to instantiate a new TypedParameterValue.
Answering my own question here. After waiting for a while and updating to the most recent library version (I'm on 2.19.2 right now) I don't have any issues anymore with the scalar types registration as I mentioned in my question, i.e.:
query.unwrap(org.hibernate.query.NativeQuery.class)
.addScalar("condition_set_ids", UUIDArrayType.INSTANCE);
So it appears to just have been a bug and I can now avoid the global registration in favor of using scalars.
Spring Data Cassandra 1.5.0 comes with a streaming API in CassandraTemplate. I'm using spring-data-cassandra 1.5.1. I have a code like:
String tableName = cassandraTemplate.getTableName(MyEntity.class).toCql();
Select select = QueryBuilder.select()
.all()
.from(tableName);
// In real world, WHERE statement is much more complex
select.where(eq(ENTITY_FIELD_NAME, expectedField))
List<MyEntity> result = cassandraTemplate.select(select, MyEntity.class);
and want to replace this code with iterable or Java 8 Stream in order to avoid fetching a big list of results to memory at once.
What I'm looking for is a method signature like CassandraOperations.stream(Select query, Class<T> entityClass), but it is not available.
The only available method in CassandraOperations accepts query string: stream(String query, Class<T> entityClass). I tried to pass here a string generated by Select like
cassandraTemplate.stream(select.getQueryString(), MyEntity.class)
But that fails with InvalidQueryException: Invalid amount of bind variables, because getQueryString() returns query with question mark placeholders instead of variables.
I see 3 options to get what I want, but every option looks bad:
Use Spring Query creation mechanism with Stream/Iterator expected return type (good only for simple queries) http://docs.spring.io/spring-data/cassandra/docs/current/reference/html/#repositories.query-methods.query-creation
Use raw CQL query and not to use QueryBuilder
Call select.getQueryString() and then substitute parameters again via BoundStatement
Is there any better way to stream selection results?
Thanks.
So, as of now the answer on my question is to wait until stable version of spring-data-cassandra 2.0.0 comes out:
https://github.com/spring-projects/spring-data-cassandra/blob/2.0.x/spring-data-cassandra/src/main/java/org/springframework/data/cassandra/core/CassandraTemplate.java#L208
I need to optimize a query that iterates over several objects and I wanted Spring Data to let the database handle it. I want to end up with a HashMap<String,String> that looks like
2134_9877, 9877
2134_2344, 2344
3298_9437, 9437
The SQL would be select convert(varchar,b.id)+'_'+convert(varchar,a.id)',a.id from t1 a join t2 b on a.jc = b.jc
So far, I've got Whatever-QL in the repository that looks like:
#Query("SELECT new map (a.bkey, a.akey) FROM mergeTable a WHERE a.discr= ?1")
The problem is, bkey is not unique, it is only unique when paired with akey and the monstrosity that I have to feed it to wants them combined with an underscore: 2345_2177.
I have tried a.bkey.toString and ''+a.bkey and new String(a.bkey) and just string(a.bkey) (that last gives a new exception but still doesn't work) but Spring doesn't like any of these. I can find no questions asking this and it seems I cannot use SQLServer's convert() function as this ain't SQL.
How can I concatenate the Integers as Strings with an underscore in this #Query?
PS: Using the native query that's been debugged in SQLServer throws some weird alias exception in Hibernate so I think 'going native' is predetermined to be a dead end.
If I have understood it right, the 'Whatever-QL' is called JPQL, and the operator CONCAT can be used. Only the use of it, as it accepts two or more parameters depends on the JPA version you are running.
Here is the answer.
JPA concat operator
You could add a getter to your entity like this:
public String getCombinedKey(){
return a.akey + "_" + a.bkey;
}
The advantage is you could handle here null's and other things if you want and it's more reusable in case you need this in another place. If you do it just in the repository you will have to copy it everytime.
Your query would then be:
#Query("SELECT new map (a.combinedKey, a.akey) FROM mergeTable a WHERE a.discr= ?1")
I am trying to execute the following query:
select MAX(CAST(T.progress AS DECIMAL)) as maxProgress from default_APN_TRACKING T where T.smartlet = 'Life-Pension Selector' GROUP BY T.trackingId
Which throws me the following Exception:
java.lang.Exception: Exception on sql query:select MAX(CAST(T.progress AS DECIMAL)) as maxProgress from default_APN_TRACKING T where T.smartlet = 'Life-Pension Selector' GROUP BY T.trackingId
Basically, i got a table with tracking IDs, and a string representing the progresses ("100.0", "66.6", "33.3", ...). For each trackingId, i want to get the highest progress.
I Agree having Integers would make more sens, but it's a constraint I have to deal with. So i tried using the CAST. Also Attempted CAST(T.progress AS DECIMAL(10,5)) without success.
The same query without the CAST works just fine, but sorts alphanumerically ("66.6" > "100.0"). How should I tackle this problem?
Thanks for the help!
EDIT: Copying the same query directly inside SQL WorkBench works perfectly. Seems like Java.sql does not like my query for some reason.
My question is about
using registered functions for date/time manipulations in Hibernate Query Language and
IntelliJ IDEA's code inspection for these registered functions in HQL.
I'm using Hibernate 4.2.5 with Java 7, and SQL Server 2008 R2 as the database, and IntelliJ IDEA 12.1.6.
In an HQL query I need to perform the TSQL DATEADD function - or the equivalent HQL date operation. This doesn't seem to exist.
Here's what I'd like to achieve:
update MyTable set startTime = GETDATE(), targetTime = DATEADD(HOUR, allocatedTime, GETDATE()), endTime = null where faultReport.faultReportId = :faultReportId and slaTypeId = :slaTypeId
Searching for answers online has been disappointingly no help, and the most common advice (like the comment seen here: https://stackoverflow.com/a/18150333/2753571) seems to be "don't use date manipulation in hql." I don't see how I can get around performing the operation in the SQL statement in the general case (e.g. when you want to update one column based on the value in another column in multiple rows).
In a similar fashion to the advice in this post: Date operations in HQL, I've subclassed a SQLServerDialect implementation and registered new functions:
registerFunction("get_date", new NoArgSQLFunction("GETDATE", StandardBasicTypes.TIMESTAMP)); // this function is a duplication of "current_timestamp" but is here for testing / illustration
registerFunction("add_hours", new VarArgsSQLFunction(TimestampType.INSTANCE, "DATEADD(HOUR,", ",", ")"));
and added this property to my persistence.xml:
<property name="hibernate.dialect" value="my.project.dialect.SqlServerDialectExtended" />
and then I'm testing with a simple (meaningless, admitted) query like this:
select x, get_date(), add_hours(1, get_date()) from MyTable x
The functions appear to be successfully registered, and that query seems to be working because the following SQL is generated and the results are correct:
select
faultrepor0_.FaultReportSLATrackingId as col_0_0_,
GETDATE() as col_1_0_,
DATEADD(HOUR,
1,
GETDATE()) as col_2_0_,
... etc.
But I now have this problem with IntelliJ IDEA: where get_date() is used in the HQL, the code inspection complains "<expression> expected, got ')'". This is marked as an error and the file is marked in red as a compilation failure.
Can someone can explain how to deal with this, please, or explain what a better approach is? Am I using the incorrect SQLFunction template (VarArgsSQLFunction)? If yes, which is the best one to use?
I'd like the usage of the registered function to not be marked as invalid in my IDE. Ideally, if someone can suggest a better way altogether than creating a new dialect subclass, that would be awesome.