In our controller logic, we have to create a few column aliases for a special class of object (Which is a compilation of many objects):
The trouble is, when trying to ransack, ransack will ignore the alias and try to go to the original table.column_name. SQL after ransack:
"SELECT CONCAT_WS('
',users.first_name,users.middle_name,users.last_name) AS conducted_by,
COUNT(NULLIF(is_complete = false,true)) as complete_count,
COUNT(staff_assessments.id) as employee_count,
staff_assessment_groups.name as name,
MIN(staff_assessments.created_at) as created_at,
staff_assessment_groups.id as staff_assessment_group_id,
staff_assessment_groups.effective_date as effective_date,
staff_assessment_groups.effective_date as review_date, 'N/A' as
store_names, true as is_complete, true as is_360_evaluation,
\"staff_assessments\".\"assigner_position_id\" FROM
\"staff_assessments\" INNER JOIN \"positions\" ON \"positions\".\"id\"
= \"staff_assessments\".\"assigner_position_id\" AND \"positions\".\"deleted_at\" IS NULL INNER JOIN \"employees\" ON
\"employees\".\"id\" = \"positions\".\"employee_id\" AND
\"employees\".\"deleted_at\" IS NULL INNER JOIN \"users\" ON
\"users\".\"id\" = \"employees\".\"user_id\" AND
\"users\".\"deleted_at\" IS NULL INNER JOIN
\"staff_assessment_groups\" ON \"staff_assessment_groups\".\"id\" =
\"staff_assessments\".\"staff_assessment_group_id\" INNER JOIN
\"survey_types\" ON \"survey_types\".\"id\" =
\"staff_assessments\".\"survey_type_id\" INNER JOIN
\"survey_type_categories_types\" ON \"survey_types\".\"id\" =
\"survey_type_categories_types\".\"survey_type_id\" WHERE
\"staff_assessments\".\"position_id\" IN (12024,) AND
\"staff_assessments\".\"is_360_evaluation\" = 't' AND
\"survey_type_categories_types\".\"survey_type_category_id\" = 3 AND
\"staff_assessments\".\"conducted_by\" IN ('Bart Simpson') GROUP BY
users.id, \"staff_assessments\".\"assigner_position_id\",
staff_assessment_groups.id ORDER BY
staff_assessment_groups.effective_date DESC LIMIT 20 OFFSET 0"
(Note the bold conducted_by--that was the original ransack search, but it is using staff_assessments.name instead of the aliased 'name' above)
So here is my question--is there way to tell ransack to use the aliased field? Or is there a way to simply create the records as an Active Relation
(Tried putting the objects to an array, but I could no longer ransack it)
Related
I have currently a query with a bunch of filters, which makes sense to use the Criteria API, unfortunately I have this query that uses a Join which uses a string value instead of a relationship. This is an example of the query:
SELECT ua.id,
COALESCE(uf.status, f.status) AS status,
r.name,
ua.companyname,
ua.firstname,
ua.lastname,
ua.usergroup,
ua.email,
ua.country,
ua.continent
FROM useraccount ua
JOIN userrole ur on ua.id = ur.userid
JOIN role r on ur.roleid = r.id and r.eventgroupid = 1
JOIN feature f on f.name = 'Locked'
LEFT JOIN userfeature uf on uf.featureid = f.id AND uf.userid = ua.id;
As you can see the problem of the query is that I want to use COALESCE operation to get a UserFeature status if present, if not use the default status from the Feature table.
The feature table is just a simple one with id, name and the status, it is only related to UserFeature and UserFeature at the same time is related to the UserAccount.
As you might guess the CriteriaAPi doesn't allows a Join<> by a regular string value. I have tried to get my mind around to get how can I change the select statement to be more aligned with what CriteriaAPI offers, but I haven't found anything on this.
I'm using PostgreSQL and Hibernate 5.4.32 (by using the spring starter jpa)
I have the following LINQ query (using EF Core 6 and MS SQL Server):
var resultSet = dbContext.Systems
.Include(system => system.Project)
.Include(system => system.Template.Type)
.Select(system => new
{
System = system,
TemplateText = system.Template.TemplateTexts.FirstOrDefault(templateText => templateText.Language == locale.LanguageIdentifier),
TypeText = system.Template.Type.TypeTexts.FirstOrDefault(typeText => typeText.Language == locale.LanguageIdentifier)
})
.FirstOrDefault(x => x.System.Id == request.Id);
The requirement is to retrieve the system matching the requested ID and load its project, template and template's type info. The template has multiple TemplateTexts (one for each translated language) but I only want to load the one matching the requested locale, same deal with the TypeTexts elements of the template's type.
The LINQ query above does that in one query and it gets converted to the following SQL query (I edited the SELECT statements to use * instead of the long list of columns generated):
SELECT [t1].*, [t2].*, [t5].*
FROM (
SELECT TOP(1) [p].*, [t].*, [t0].*
FROM [ParkerSystems] AS [p]
LEFT JOIN [Templates] AS [t] ON [p].[TemplateId] = [t].[Id]
LEFT JOIN [Types] AS [t0] ON [t].[TypeId] = [t0].[Id]
LEFT JOIN [Projects] AS [p0] ON [p].[Project_ProjectId] = [p0].[ProjectId]
WHERE [p].[SystemId] = #__request_Id_1
) AS [t1]
LEFT JOIN (
SELECT [t3].*
FROM (
SELECT [t4].*, ROW_NUMBER() OVER(PARTITION BY [t4].[ReferenceId] ORDER BY [t4].[Id]) AS [row]
FROM [TemplateTexts] AS [t4]
WHERE [t4].[Language] = #__locale_LanguageIdentifier_0
) AS [t3]
WHERE [t3].[row] <= 1
) AS [t2] ON [t1].[Id] = [t2].[ReferenceId]
LEFT JOIN (
SELECT [t6].*
FROM (
SELECT [t7].*, ROW_NUMBER() OVER(PARTITION BY [t7].[ReferenceId] ORDER BY [t7].[Id]) AS [row]
FROM [TypeTexts] AS [t7]
WHERE [t7].[Language] = #__locale_LanguageIdentifier_0
) AS [t6]
WHERE [t6].[row] <= 1
) AS [t5] ON [t1].[Id0] = [t5].[ReferenceId]
which is not bad, it's not a super complicated query, but I feel like my requirement can be solved with a much simpler SQL query:
SELECT *
FROM [Systems] AS [p]
JOIN [Templates] AS [t] ON [p].[TemplateId] = [t].[Id]
JOIN [TemplateTexts] AS [tt] ON [p].[TemplateId] = [tt].[ReferenceId]
JOIN [Types] AS [ty] ON [t].[TypeId] = [ty].[Id]
JOIN [TemplateTexts] AS [tyt] ON [ty].[Id] = [tyt].[ReferenceId]
WHERE [p].[SystemId] = #systemId and tt.[Language] = 2 and tyt.[Language] = 2
My question is: is there a different/simpler LINQ expression (either in Method syntax or Query syntax) that produces the same result (get all info in one go) because ideally I'd like to not have to have an anonymous object where the filtered sub-collections are aggregated. For even more brownie points, it'd be great if the generated SQL would be simpler/closer to what I think would be a simple query.
Is there a different/simpler LINQ expression (...) that produces the same result
Yes (maybe) and no.
No, because you're querying dbContext.Systems, therefore EF will return all systems that match your filter, also when they don't have TemplateTexts etc. That's why it has to generate outer joins. EF is not aware of your apparent intention to skip systems without these nested data or of any guarantee that these systems don't occur in the database. (Which you seem to assume, seeing the second query).
That accounts for the left joins to subqueries.
These subqueries are generated because of FirstOrDefault. In SQL it always requires some sort of subquery to get "first" records of one-to-many relationships. This ROW_NUMBER() OVER construction is actually quite efficient. Your second query doesn't have any notion of "first" records. It'll probably return different data.
Yes (maybe) because you also Include data. I'm not sure why. Some people seem to think Include is necessary to make subsequent projections (.Select) work, but it isn't. If that's your reason to use Includes then you can remove them and thus remove the first couple of joins.
OTOH you also Include system.Project which is not in the projection, so you seem to have added the Includes deliberately. And in this case they have effect, because the entire entity system is in the projection, otherwise EF would ignore them.
If you need the Includes then again, EF has to generate outer joins for the reason mentioned above.
EF decides to handle the Includes and projections separately, while hand-crafted SQL, aided by prior knowledge of the data could do that more efficiently. There's no way to affect that behavior though.
This LINQ query is close to your SQL, but I'm afraid of correctness of the result:
var resultSet =
(from system in dbContext.Systems
from templateText in system.Template.TemplateTexts
where templateText.Language == locale.LanguageIdentifier
from typeText in system.Template.Type.TypeTexts
where typeText.Language == locale.LanguageIdentifier
select new
{
System = system,
TemplateText = templateText
TypeText = typeText
})
.FirstOrDefault(x => x.System.Id == request.Id);
I have a view defined as below
CREATE VIEW DQ_DB.DQM_RESULT_VIEW
AS SELECT
res.ACTIVE_FL AS ACTIVE_FL,
res.VERSION as VERSION,
res.rule_constituents_tx,
nvl(ruletable.rule_desc,'N/A') AS rule_ds,
nvl(res.effective_dt, TO_DATE('31-dec-9999','dd-mon-yyyy')) AS effective_dt,
nvl(res.rule_id,'N/A') AS rule_id,
res.audit_update_ts AS rule_processed_at,
res.load_dt,
res.vendor_group_key,
nvl(res.vendor_entity_key,'N/A') AS vendor_entity_key,
res.vendor_entity_producer_nm,
(SELECT category_value_tx FROM dq_db.category_lookup_view WHERE category_nm = 'RESULT_STATUS_NB' AND category_value_cd = res.result_status_nb ) AS result,
--catlkp.category_value_tx as result,
res.entity_type,
nvl(rgrp.grp_nm,'N/A') AS rule_category,
nvl(ruletable.rule_nm,'N/A') AS rule_nm,
feedsumm.feed_run_nm AS file_nm,
res.application_id AS application,
res.data_source_id AS datasource,
res.entity_nm,
res.rule_entity_effective_dt,
res.result_id,
dim.dimension_nm,
dim.sub_dimension_nm,
ruletable.execution_env AS execution_env,
ruletable.ops_action AS ops_action,
rulefunctiontable.func_nm AS rule_func_nm,
-- nvl2(res.primary_dco_sid,dq_db.get_dco_name(res.primary_dco_sid),null) AS dco_primary,
-- nvl2(res.delegate_dco_sid,dq_db.get_dco_name(res.delegate_dco_sid),null) AS dco_delegate,
res.primary_dco_sid AS dco_primary,
res.delegate_dco_sid AS dco_delegate,
ruletable.data_concept_id AS data_concept_id,
res.latest_result_fl as latest_result_fl,
res.batch_execution_ts as batch_execution_ts
FROM
dq_db.dqm_result res
--LEFT OUTER JOIN dq_db.category_lookup_view catlkp on (catlkp.category_nm = 'RESULT_STATUS_NB' AND catlkp.category_value_cd = res.result_status_nb)
LEFT OUTER JOIN dq_db.feed_run_summary feedsumm ON res.vendor_group_key = feedsumm.batch_id
LEFT OUTER JOIN dq_db.dqm_rule ruletable ON res.rule_id = ruletable.rule_id
LEFT OUTER JOIN dq_db.dqm_rule_grp rgrp ON ruletable.rule_grp_id = rgrp.rule_grp_id
LEFT OUTER JOIN dq_db.dqm_rule_function rulefunctiontable ON ruletable.func_id = rulefunctiontable.func_id
LEFT OUTER JOIN dq_db.dq_dimension_view dim ON dim.dimension_id = ruletable.dimension_id
result column of view is a lookup value generated from subquery condition which translates code as
below.
0|PASS 1|ALERT 2|ERROR
My web application adds few predicates to this view which are pushed to base tables. But one particular predicate on view shown below is not pushed due to inline nature of the predicate.
select * from dqm_result_view where result IN ('ALERT','ERROR')
Right now this query applies filter after view JOINs are executed as there is no way to push predicate to DQM_RESULT table.
What is need is.. if we get that result predicate then apply code 0,1,2 instead of applying result predicate at end so that data is filtered ahead of time for JOINs from DQM_RESULT base table and thus improve performance. Any idea on how to achieve this?
I want to do a Linq query that joins three tables, but only returns data from two of them (the third is only joined for ordering purposes). I'm trying to order by columns that aren't in the output of the produced query, but they seem to be ignored:
var records = from q in _pdxContext.Qualifier
join aql in _pdxContext.ApplicationQualifierLink on q.Id equals aql.QualifierId
join qt in _pdxContext.QualifierType on q.QualifierTypeId equals qt.Id
where SOME_LIST.Contains(aql.ApplicationId)
orderby aql.Sequence
select new Qualifier
{
Id = q.Id,
QualifierType = new QualifierType
{
Id = qt.Id, Value = qt.Value
}
};
return records.Distinct().ToList();
The output SQL from this does NOT have an ORDER BY clause.
If I change the orderby to read like so:
orderby q.Id
... then the output SQL has the order by clause.
Does Linq ignore orderby statements when the mentioned columns aren't used in the output (as appears to be the case here)? If so, how do I order by columns not in the output?
It seems this is an SQL limitation. The error from the SQL Server engine:
"ORDER BY items must appear in the select list if SELECT DISTINCT is specified."
So, as written, I can't do what I want to do.
I ended up using:
using (var cnn = new SqlConnection(_connectionString))
{
string sql = #"select
min(q.Id) Id, q.QualifierTypeId, q.QualifierTypeId, min(q.AcaId) AcaId,
q.QualifierTypeId Id, qt.Value
from
qdb.Qualifier q
inner join qdb.QualifierType qt on qt.Id = q.QualifierTypeId
inner join ApplicationQualifierLink l on l.QualifierId = q.id
where l.ApplicationId in (" + string.Join(",", applicationIds) + #")
group by q.Text, q.QualifierTypeId, qt.Value";
qualifiers = cnn.Query<Qualifier, QualifierType, Qualifier>(sql,
(qualifier, type) =>
{
qualifier.QualifierType = type; return qualifier;
}
).ToList();
}
Note: When you attempt to use order by and distinct as in my original clause, no error is given, entity framework silently discards the order by without any error.
SELECT t_PersonalInformation.personalInformation_Name, t_PersonalInformation.personalInformation_PresentAddress,
t_PersonalInformation.personalInformation_PermanentAddress, t_PersonalInformation.personalInformation_Phone,
t_PersonalInformation.personalInformation_Email,
t_Applicant.applicant_TotalExperience,
t_Experience.experience_CompanyName, CAST( t_Experience.experience_EndingYear AS INT) - CAST( t_Experience.experience_JoiningYear AS INT) AS yearOfExperience ,
t_Experience.experience_Responsibilities,
t_Training.training_TitleDetails, t_Training.training_Institute,
t_Training.training_Year, t_Training.training_Duration
FROM t_Applicant LEFT OUTER JOIN
t_PersonalInformation ON t_Applicant.applicant_user_ID = t_PersonalInformation.personalInformation_applicant_ID
LEFT OUTER JOIN
t_Experience ON t_Applicant.applicant_user_ID = t_Experience.experience_applicant_ID
LEFT OUTER JOIN
t_Training ON t_Applicant.applicant_user_ID = t_Training.training_applicant_ID
WHERE (t_Applicant.applicant_user_ID = 'hasib789')
i am using in C# with VS2008
I don't really have the time to go through all of that, but I can give you an idea of how it's done.
var query = from var applicant in t_Applicant
from perInf in t_PersonalInformation.Where(per => applicant.applicant_user_ID = per.personalInformation_applicant_ID).DefaultIfEmpty()
where applicant.applicant_user_ID == "hasib789"
select new ClassName{
Name = perInf!=null ? perInf.personalInformation_Name : <default value>,
PresentAddress = perInf!=null ? perInf.personalInformation_PresentAddress: <default value>,
...
etc
}
That second 'from' statement is one of the ways to do an outer join. That DefaultIfEmpty allows it to generate a new record of ClassName even if no matching record for perInf is found. Once you actually go to assign the values in your new record at the bottom, you have to check for null.
Using that template you should be able to get the rest of the query built.