I have a sql query like this
select column from table where path = left('INPUTSTRING', length(path));
and trying to accomplish it in hql like this,
return session.createQuery("from Table where Path = left(:input, length(Path))").
query.setParameter("input", inputPath).
.list();
and getting an error like this
Caused by: org.hibernate.hql.ast.QuerySyntaxException: unexpected token: left near line 1
how to get this done? What is the corresponding string function in hql? Is there a solution for this using criteria query apis?
Yes, left() is not supported by the MySQLDialect. See the list of HQL supported functions on API docs.
Now you have left with 2 options.
Use session.createSQLQuery() method.
Create Your own Dialect class by extending the MySQLDialect and register the function there. This is told at hibernate forum here explained well in a blog post here.
I'm not sure if HQL does this for you , but you can use IQuery/session.CreateSQLQuery() to use a raw SQL query to populate a mapped entity. I've never used it for substrings, but have used it for aggregate functions. Check chapter 13 of the NHibernate docs and see if that does it for you. You can check the query substitution available in Nhibernate - here
Related
Can any Laravel developers help me understand why the following SQL statement is not working. I don't get any errors, it simply doesn't do what it should:
DB::table('devices')
->leftJoin('hotel_device','hotel_device.device_id','devices.id')
->where("hotel_device.device_id","IS","NULL")
->delete();
This should remove all device ids where the leftJoin link returns as NULL (ie. where this device id is not being used in the "hotel_device" table).
If I run it as raw SQL directly in the database it works correctly. Note the "IS" condition rather than "=" condition, as I am refering to a NULL value. (using "=" didn't find any matching rows)
thanks.
You should use the whereNull method to compare to null rather than trying to filter it using the regular where method.
DB::table('devices')
->leftJoin('hotel_device','hotel_device.device_id','devices.id')
->whereNull("hotel_device.device_id")
->delete();
I'm trying to make a N1QL based query on Spring Data Couchbase. The documentation says
#n1ql.fields will be replaced by the list of fields (eg. for a SELECT clause) necessary to reconstruct the entity.
My repository implementation is this one:
#Query("#{#n1ql.fields} WHERE #{#n1ql.filter}")
List<User> findAllByFields(String fields);
And I'm calling this query as follows:
this.userRepository.findAllByFields("SELECT firstName FROM default");
I'm getting this error:
Caused by: org.springframework.data.couchbase.core.CouchbaseQueryExecutionException: Unable to execute query due to the following n1ql errors:
{"msg":"syntax error - at AS","code":3000}
After a little bit of researching, I also tryed:
#Query("SELECT #{#n1ql.fields} FROM #{#n1ql.bucket} WHERE #{#n1ql.filter}")
With this query, I don't get an error, I get all the documents stored but only the ID the other fields are set to null, when my query tries to get the firstName field.
this.userRepository.findAllByFields("firstName");
Anyone knows how to do such a query?
Thank you in advance.
You're misunderstanding the concept, I encourage you to give the documentation more time and see more examples. I'm not sure what exactly you're trying to achieve but I'll throw some examples.
Find all users (with all of their stored data)
#Query("#{#n1ql.selectEntity} WHERE #{#n1ql.filter}")
List<User> findAllUsers();
This will basically generate SELECT meta().id,_cas,* FROM bucket WHERE type='com.example.User'
Notice findAllUsers() does not take any parameters because there are no param placeholders defined in the #Query above.
Find all users where firstName like
#Query("#{#n1ql.selectEntity} WHERE #{#n1ql.filter} AND firstName like $1")
List<User> findByFirstNameLike(String keyword);
This will generate something like the above query but with an extra where condition firstName like
Notice this method takes a keyword because there is a param placeholder defined $1.
Notice in the documentation it says
#{#n1ql.selectEntity} WHERE #{#n1ql.filter} AND test = $1
is equivalent to
SELECT #{#n1ql.fields} FROM #{#n1ql.bucket} WHERE
#{#n1ql.filter} AND test = $1
Now if you don't want to fetch all the data for user(s), you'll need to specify the fields being selected, read following links for more info
How to fetch a field from document using n1ql with spring-data-couchbase
https://docs.spring.io/spring-data/couchbase/docs/2.2.4.RELEASE/reference/html/#_dto_projections
I think you should try below query, that should resolve the issue to get fields based parameter you have sent as arguments.
Please refer blow query.
#Query("SELECT $1 FROM #{#n1q1.bucket} WHERE #{#n1ql.filter}")
List findByFirstName(String fieldName);
Here, bucket name resolve to the User entity and and n1ql.filter would be a default filter.
I have a JSONB column which holds arrays of strings, eg: ["foo", "bar"]
I want to write the jOOQ equivalent of:
SELECT * FROM sometable WHERE somecolumn ?| <mylist>
...where should be bound to a java List of string tag names.
There doesn't appear to be any direct support for ?| in jOOQ 3.8. I have looked at binding to raw sql in a condition but I'm not quite sure the syntax; it gets even worse if trying to use the ? postgres operator which conflicts with the binding expression.
UPDATE: the stacktrace with 3.8.3
I stripped this down to a minimal test. When adding a condition like this using jOOQ 3.8.3:
query.addConditions(DSL.condition("sometable.tags ?| array['sometag']"));
Produces a stacktrace like this:
Caused by: org.postgresql.util.PSQLException: No value specified for parameter 1.
at org.postgresql.core.v3.SimpleParameterList.checkAllParametersSet(SimpleParameterList.java:228)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:163)
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:622)
at org.postgresql.jdbc.PgStatement.executeWithFlags(PgStatement.java:472)
at org.postgresql.jdbc.PgStatement.execute(PgStatement.java:465)
at org.jooq.tools.jdbc.DefaultPreparedStatement.execute(DefaultPreparedStatement.java:194)
at org.jooq.impl.AbstractResultQuery.execute(AbstractResultQuery.java:269)
at org.jooq.impl.AbstractQuery.execute(AbstractQuery.java:348)
... 36 more
An issue related to jOOQ parsing ?| and similar operators as bind variables has been addressed in jOOQ 3.8.3: https://github.com/jOOQ/jOOQ/issues/5307
JDBC limitation
Note, in addition to the above, there is also a JDBC limitation that I have documented in a separate question. In jOOQ, you can work around this JDBC limitation by specifying:
Settings settings = new Settings().withStatementType(StatementType.STATIC_STATEMENT);
See also: http://www.jooq.org/doc/latest/manual/sql-execution/statement-type
Or, alternatively, by falling back to using the jsonb_exists_any() function instead of the ?| operator.
I'm using Hibernate but doing a simple SQLQuery, so I think this boils down to a basic JDBC question. My production app runs on MySQL but my test cases use an in memory HSQLDB. I find that a SELECT COUNT operation returns BigInteger from MySQL but Long from HSQLDB.
MySQL 5.5.22
HSQLDB 2.2.5
The code I've come up with is:
SQLQuery tq = session.createSQLQuery(
"SELECT COUNT(*) AS count FROM calendar_month WHERE date = :date");
tq.setDate("date", eachDate);
Object countobj = tq.list().get(0);
int count = (countobj instanceof BigInteger) ?
((BigInteger)countobj).intValue() : ((Long)countobj).intValue();
This problem of the return type negates answers to other SO questions such as getting count(*) using createSQLQuery in hibernate? where the advice is to use setResultTransformer to map the return value into a bean. The bean must have a type of either BigInteger or Long, and fails if the type is not correct.
I'm reluctant to use a cast operator on the 'COUNT(*) AS count' portion of my SQL for fear of database interoperability. I realise I'm already using createSQLQuery so I'm already stepping outside the bounds of Hibernates attempts at database neutrality, but having had trouble before with the differences between MySQL and HSQLDB in terms of database constraints
Any advice?
I don't known a clear solution for this problem, but I will suggest you to use H2 database for your tests.
H2 database has a feature that you can connect using a compatibility mode to several different databases.
For example to use MySQL mode you connect to the database using this jdbc:h2:~/test;MODE=MySQL URL.
You can downcast to Number and then call the intValue() method. E.g.
SQLQuery tq = session.createSQLQuery("SELECT COUNT(*) AS count FROM calendar_month WHERE date = :date");
tq.setDate("date", eachDate);
Object countobj = tq.list().get(0);
int count = ((Number) countobj).intValue();
Two ideas:
You can get result value as String and then parse it to Long or BigInteger
Do not use COUNT(*) AS count FROM ..., better use something like COUNT(*) AS cnt ... but in your example code you do not use name of result column but it index, so you can use simply COUNT(*) FROM ...
I'm building a search feature for my Symfony2 project, and I wrote the SQL for it as follows:
SELECT dlc.title, dlc.description, dlc.keywords
FROM ShoutMainBundle:Dlc dlc
WHERE MATCH (dlc.title, dlc.description, dlc.keywords) AGAINST (":keyword" IN BOOLEAN MODE)
AND dlc.type = (":audio")
ORDER BY dlc.date DESC
However, when I run this in the project the following error is given:
[Syntax Error] line 0, col 96: Error: Expected known function, got
'MATCH'
Is there an alternative I could use instead of MATCH? At the moment (just so I can do basic testing) I'm using LIKE, but it doesn't work too well if it's more than one word being used to search with.
EDIT:
This is how the code is used within the code:
$em = $this->getDoctrine()->getEntityManager();
$wckeyword = '%'.$skeyword.'%';
$dlcresult = $em->createQuery('
SELECT dlc.title, dlc.description, dlc.keywords
FROM ShoutMainBundle:Dlc dlc
WHERE MATCH (dlc.title, dlc.description, dlc.keywords) AGAINST (":keyword" IN BOOLEAN MODE)
AND dlc.type = (":audio")
ORDER BY dlc.date DESC'
)->setParameters(array('type' => $stype, 'keyword' => $wckeyword));
$dlcres = $dlcresult->getResult();
Doctrine doesn't support that out-of-the-box, true. But you can:
Create custom functions for DQL yourself
Use native SQL and custom hydration
This is not currently possible with Doctrine2 ORM. As Doctrine supports many different database vendors and most of them don't have a FULLTEXT search feature, it's not supported at all.
You can always use Doctrine2 DBAL for searching. You lose all these nifty orm features, but in my practice they aren't that needed in searching situations anyway.