I'm new to cosmosdb so bear with me. Here's what I'm trying to do. I have a document that has an array value. Here's the query
select value c.NodeIds from c where c.PartitionKey = 'contentlink' and c.id = '123'
I want to use this result in my where statement, but I'm having trouble understanding how to do this. Here's what I tried to come up with.
SELECT c.*
FROM c
where c.PartitionKey = 'node'
and c.id in (select value n from n in c.NodeIds where c.PartitionKey = 'contentlink' and c.id = '123')
Related
TableAlias isn't working with multiple joins.
The query:
var q = Db.From<Blog>(Db.TableAlias("b"))
.LeftJoin<Blog, BlogToBlogCategory>((b,btb)=> b.Id == btb.BlogId, Db.TableAlias("btbc"))
.Join<BlogToBlogCategory, BlogCategory>((bt,bc)=>bt.BlogCategoryId == bc.Id, Db.TableAlias("cats"))
.GroupBy(x => x.Id);
.Select("b.*, json_agg(cats) as BlogCategoriesJson");
var results = Db.Select<BlogQueryResponse>(q);
Generates this SQL:
SELECT b.*, json_agg(cats) as BlogCategoriesJson
FROM "blog" "b" LEFT JOIN "blog_to_blog_category" "btbc" ON ("b"."id" = "btbc"."blog_id") INNER JOIN "blog_category" "cats" ON ("blog_to_blog_category"."blog_category_id" = "cats"."id")
GROUP BY "b"."id"
This causes error because it is referencing "blog_to_blog_category" instead of btbc
The Db.TableAlias() only provides an alias for the target join table, your inner join does not specify the alias to use for the source table so it references the full table name as expected.
You can use Sql.TableAlias() in your LINQ Expression to reference a table alias, e.g:
var q = Db.From<Blog>(Db.TableAlias("b"))
.LeftJoin<Blog, BlogToBlogCategory>((b,btb)=> b.Id == btb.BlogId, Db.TableAlias("btbc"))
.Join<BlogToBlogCategory, BlogCategory>((bt,bc)=>
Sql.TableAlias(bt.BlogCategoryId, "btbc") == bc.Id, Db.TableAlias("cats"))
.GroupBy(x => x.Id);
.Select("b.*, json_agg(cats) as BlogCategoriesJson");
I am trying to make this query in OrmLite:
select b.* from blog b
join blog_to_blog_category btbc on b.id = btbc.blog_id
join blog_category bc on btbc.blog_category_id = bc.id
where b.url like '%.com' and bc.id in (100, 583)
group by b.id
having count(distinct bc.id ) = 1
I can't figure out how to get the Having() method structured. I can see there is a Sql.CountDistinct() method but I can't figure out how to use it with Having().
I figure I need to do something along the lines of:
var q = db
.From<Blog>()
.LeftJoin<BlogToBlogCategory>()
.Join<BlogToBlogCategory, BlogCategory>()
.Where<BlogCategory>(x => Sql.In(x.Id, 100, 583))
.GroupBy<Blog>(bc => bc.Id)
.Having(x => Sql.CountDistinct("blog_category.id") == "2")
This gives error:
42883: operator does not exist: bigint = text
I can't see how to type it to take a table column name and return a number for comparison.
Is this query possible?
EDIT
I got around it by setting having expression explicitly
q.HavingExpression = $"having count(distinct {q.Table<BlogCategory>()}.{q.Column<BlogCategory>(bc => bc.Id)}) = 2";
I am still curious though if it is possible to do this with fluent api.
I've just added multiple typed table overloads for Having() in the latest v5.11.1 that's now available on MyGet which will allow you to reference a joined table properties in a typed expression, e.g:
var q = db
.From<Blog>()
.LeftJoin<BlogToBlogCategory>()
.Join<BlogToBlogCategory, BlogCategory>()
.Where<BlogCategory>(x => Sql.In(x.Id, 100, 583))
.GroupBy<Blog>(bc => bc.Id)
.Having<BlogCategory>(x => Sql.CountDistinct(x.Id) == 2)
All of the documentation for Cosmos DB and it looks like it only supports the JOINkeyword, which seems to be a sort of INNER JOIN.
I have the following query:
SELECT * FROM
(
SELECT
DISTINCT(c.id),
c.OtherCollection,
FROM c
JOIN s IN c.OtherCollection
)
AS c order by c.id
This works fine and returns the data of documents that have OtherCollection populated. But It obviously does not return any documents that do not have it populated.
The reason for the join is that sometimes I execute the following query (queries are built up from user input)
SELECT * FROM
(
SELECT
DISTINCT(c.id),
c.OtherCollection,
FROM c
JOIN s IN c.OtherCollection
WHERE s.PropertyName = 'SomeValue'
)
AS c order by c.id
The question is how can I have a sort of LEFT JOIN operator in this scenario?
CosmosDB JOIN operation is limited to the scope of a single document. What possible is you can join parent object with child objects under same document.
It is totally different from SQL Join query which supports across two/many tables.
You can simulate LEFT JOIN with the EXISTS sentence.
Eg:
SELECT VALUE c
FROM c
WHERE (
(c.OtherCollection = null) OR EXISTS (--Like a "Left Join"
SELECT null
FROM s IN c.OtherCollection
WHERE s.PropertyName = 'SomeValue'
)
)
--AND/OR Some other c Node conditions
order by c.id
I want to get the list of all Branch even if they have no accounts with user role
Query query = em.createQuery("SELECT NEW com.package.BranchInstructors(b,a) FROM Branch b LEFT JOIN b.accounts a WHERE b.dFlg = 0 AND a.userRole = :role ORDER BY b.name ASC");
query.setParameter("role", "user");
return query.getResultList();
Unfortunately it's returning only Branches with user role, it's like doing INNER JOIN instead.
Any idea what's going on?
just add the a.userRole is null condition to your query to avoid filtering the null userRole that you got from the left join
SELECT NEW com.package.BranchInstructors(b,a)
FROM Branch b
LEFT JOIN b.accounts a
WHERE b.dFlg = 0
AND (a.userRole = :role OR a.userRole IS NULL)
ORDER BY b.name ASC"
The problem is in your WHERE vs LEFT JOIN clause.
If you use LEFT JOIN table Accounts and use this table in the WHERE with AND condition, it behaves like a JOIN.
So, you can use WITH in the LEFT JOIN:
Query query = em.createQuery("SELECT NEW com.package.BranchInstructors(b,a) FROM Branch b
LEFT JOIN b.accounts a WITH a.userRole = :role
WHERE b.dFlg = 0 ORDER BY b.name ASC");
Here is a SQL Query I want to convert to EF4.3
command = database.GetSqlStringCommand(#"
select
H.AUTHENTICATION_ID,
USERNAME,
PERMISSIONS,
ORGANIZATION_IDENTIFIER,
O.ORGANIZATION_ID
from
AUTHENTICATION H
left join [AUTHORIZATION] T on H.AUTHENTICATION_ID=T.AUTHENTICATION_ID
join ORGANIZATION O on O.ORGANIZATION_ID = T.ORGANIZATION_ID
order by H.AUTHENTICATION_ID");
Here is the best LINQ I could come up with:
var query = from h in context.Authentications
join t in context.Authorizations on h.AuthenticationId equals t.Authentications.AuthenticationId
join o in context.Organizations on t.Organizations.OrganizationId equals o.OrganizationId
orderby
h.AuthenticationId
select new
{ AUTHENTICATION_ID = (Int16?)h.AuthenticationId,
h.Username,
t.Permissions,
o.OrganizationIdentifier,
OrganizationID = (Int16?)o.OrganizationId
};
I know i need to merge my first join (between Authorizations & Authentications) into, lets say x and apply DefaultIfEmpty but can't make out the syntax.
EDIT: Image for clarification:
Any help will be highly appreciated. Regards.
The basic syntax for a "left join" in Linq is like this:
from x in table1
join y in table2 on x.id equals y.id into jointable
from z in jointable.DefaultIfEmpty()
select new
{
x.Field1,
x.Field2,
x.Field3,
Field4 = z == null ? 0 : z.Field4
};
In your case, I'm a little confused because the entity relations you seem to be using in your Linq don't match the ones implied by your SQL; are the relationships here zero-or-one, zero-or-many, one-to-one, etc? Specifically, you're doing this:
from h in context.Authentications
join t in context.Authorizations on h.AuthenticationId equals t.Authentications.AuthenticationId
but your SQL implies that "Authentication" is the parent here with zero-or-more "Authorization" children, not the other way around, which would be more like:
from h in context.Authentications
from t in h.Authorizations.DefaultIfEmpty()
If you can give us a better idea of the data model and what data you expect to get out of it we can more easily explain how that query would look in Linq. Assuming that your relationships match what is implied by the SQL, you should be able to get what you want using the following Linq queries:
var query = from h in context.Authentications
from t in h.Authorizations.DefaultIfEmpty()
select new
{
h.AuthenticationId,
h.Username,
Permissions = t == null ? null : t.Permissions,
Organizations = t == null ? new EntitySet<Organization>() : t.Organizations
};
var query2 = from x in query
from o in x.organizations.DefaultIfEmpty()
select new
{
AUTHENTICATION_ID = (short?)x.AuthenticationId,
x.Username,
x.Permissions,
OrganizationIdentifier = o == null ? null : o.OrganizationIdentifier,
OrganizationID = o == null ? (short?)null : o.OrganizationID
};
Given the foreign keys that exist in the question diagram, how about something like this?
var query = from a in context.Authentications
select new
{
a.AuthenticationID,
a.Username,
a.Authorisations.Permissions ?? false,
a.Authorisations.Organisations.OrganisationIdentifier ?? 0
a.Authorisations.Organisations.OrganisationID ?? 0
};
I went ahead and moved the entire query to a Stored Procedure on the database. This solves the problem by avoiding LINQ and ObjectBuilder in the first place.