I have this tables at sql server:
id_service name
1 ejemplo 1
2 ejemplo 2
id_service id_quality
1 1
1 2
id_quality quality
1 simple
2 full
and Im trying to get this:
id_service qualities
1 Simple \n Full
I´m working with linq, is there any way to do it???
I have this so far, but it returns two rows instead of one as I need
var services = from service in dc.service
join s_quality in dc.service_quality
on service.id_service equals s_quality.id_service
join qualityObj in dc.quality
on s_quality.id_quality equals qualityObj.id_quality
select new {service.id_service, qualityObj.quality1};
GridView1.DataSource = services;
GridView1.DataBind();
The ending grid should look like this:
id_service name quality available
1 Company 1 1 - simple
2 - full
--------------------------------------------------------
2 Company 2 1 - simple
(this column should have grouped or concat results)
var servicios = from servicio in dc.servicio
join s_calidad in dc.servicio_calidad
on servicio.id_servicio equals s_calidad.id_servicio
join calidadObj in dc.calidad
on s_calidad.id_calidad equals calidadObj.id_calidad
group new {servicio.id_servicio, calidadObj.calidad1} by servicio.id_servicio into grouping
select new { groupning.Key, Concat = string.Join(",", grouping.Select(g => g.calidad1)) };
You can write your own concatenation logic for Concat property in the anonimous type
Related
There are two tables and using linq query to get records. From second table, there can be multiple rows corresponding to first table with date timestamp... based on below query, I am getting all records, but is there a way we can get the row from second table which has latest timestamp ?
Table Parent
ID Name
1 M
2 N
3 O
4 P
5 Q
Table Child
Id fkID DateTime
1 2 01/12/2021 09:12:20
2 2 01/12/2021 09:13:20
3 2 01/12/2021 09:14:20
4 2 01/12/2021 09:15:20
5 2 01/12/2021 **09:16:20**
Linq query:
from p in Parent
join c in Child on p.id equals c.fkId into cJoin
from cJoin in cJoin.DefaultIfEmpty()
select new TempResponse
{
Id = p.Id,
Name = p.Name,
Date = c.Date
}
I am getting 10 records using above query but just need 5 records i.e. from child table instead of all 5 records, we need a record that has latest time stamp
**expected output**
1 M
2 N 01/12/2021 09:16:20
this record is 5'th record from child table because this one has latest date time stamp
( latest record )
3 O
4 P
5 Q
Is there any way we can use group by and get the record that has latest time stamp from second table ?
Assuming you have defined navigation properties for the FK, I would use a query like;
dbContext.Child.Where(c => c.Date == c.Parent.Child.Max(c2 => c2.Date))
I believe you can use:
var ans = from p in Parent
join cmax in (
from c in Child
group c by c.fkId into cg
select cg.OrderByDescending(c => c.Date).FirstOrDefault())
on p.Id equals cmax.fkId into cJoin
from c in cJoin.DefaultIfEmpty()
select new TempResponse {
Id = p.Id,
Name = p.Name,
Date = c != null ? c.Date : null
};
Note that the order of results seems to vary on SQL Server unless you add another orderby clause before the select to force an order.
I am trying to do the following but I cannot manage to get it right yet :(.
I have these tables:
table1 -> tb1_id, tb1_name
Sample Data:
--------------
1 group1
2 group2
3 group3
4 group4
5 group5
table2 -> tb2_id, tb2_sector, tb2_tb3_id
Sample Data:
--------------
1 alpha 1
2 beta 2
3 gamma 2
4 delta 2
5 epsilon 4
table3 -> tb3_id, tb3_mid, tb3_section
Sample Data:
--------------
1 234 alpha,beta,gama,delta
This is the output that I am looking for:
Name Count %
------ ----- -----
group1 1 25%
group2 3 75%
group3 0 0%
group4 0 0%
group5 0 0%
Basically I need a split a column value delimited by a comma (tb3_section in table3) and then find the right group for each value (table2 gives me the group id to link with table1) and then do a total count by group and get the percentage (assuming total is 100%).
This is the query I tried so far:
I searched for split value samples and found one that does the split by creating a numbers table first:
create table numbers (
`n` INT(11) SIGNED
, PRIMARY KEY(`n`)
)
INSERT INTO numbers(n) SELECT #row := #row + 1 FROM
(SELECT 0 UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) t,
(SELECT 0 UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) t2,
(SELECT 0 UNION ALL SELECT 1) t8,
(SELECT #row:=0) ti;
Afterwards, I did this:
select tb3_section, count(1) from (
select
tb3_mid,
substring_index(
substring_index(tb3_section, ',', n),
',',
-1
) as tb3_section from table3
join numbers
on char_length(tb3_section)
- char_length(replace(tb3_section, ',', ''))
>= n - 1
) tb3_section_dashboard
group by 1
This doesn't give me the group count. Just does the split of tb3_section but doesn't give me the correct count and equivalent percentage. Any ideas will be much appreciate it thanks a lot.
LATEST UPDATE
First of all, I would like to thanks #eggyal for pointing me to the right direction and #Shadow for despise knowing that I was not taking the best approach, he came up with a quick fix to my problem. I managed to change the approach and removed the comma delimited values from table3. Instead now I add multiple rows for each new value (and added a constraint to avoid duplicates).
Now table3 looks like:
Sample Data:
--------------
1 234 alpha
2 234 beta
3 234 gama
4 234 delta
5 235 alpha
Here is the query I have taken from #shadow sample:
SELECT t1.tb1_name, COUNT(t3.tb3_section) AS no_per_group,
COUNT(t3.tb3_section) / t4.no_of_groups AS percentage
FROM t1 left
JOIN t2 ON t1.tb1_id=t2.tb2_tb3_id
INNER JOIN t3 ON t2.tb2_sector=t3.tb3_section>0
JOIN (SELECT COUNT(*) AS no_of_groups
FROM t3 INNER JOIN t2 ON t2.tb2_sector=t3.tb3_section>0) t4
GROUP BY t1.tb1_name
Instead of using find_in_set now I use = to match the exact value.
Now I get something like the following but the percentage looks odd and I miss a group that doesn't have a match:
Name no_per_group percentage
----- ------------- ----------
group1 2 0.1053
group3 3 0.1579
group4 3 0.1579
group5 3 0.1579
Although still I need something like:
Name Count %
------ ----- -----
group1 1 25%
group2 3 75%
group3 0 0%
group4 0 0%
group5 0 0%
Notice that if there is no match in a group, I still need to show that group.
Because I have thousands of records which are different from each other, I need to add another condition: where tb3_mid=234 . Likes this, the results are using to tb3_mid.
The best solution would be to redesign your table structure and move the data in the delimited values list to a separate table.
The quick solution is to utilise MySQL's find_in_set() function.
To get the total count of entries in the messages table (table3):
select count(*) as no_of_groups
from t3 inner join t2 on find_in_set(t2.tb2_sector,t3.tb3_section)>0
To get the counts per group, add a join to table1 and group by group name. To calculate the percentage, add the above query as a subquery:
select t1.tb1_name, count(t3.tb3_section) as no_per_group, count(t3.tb3_section) / t4.no_of_groups as percentage
from t1 left join t2 on t1.tb1_id=t2.tb2_tb3_id
inner join t3 on find_in_set(t2.tb2_sector,t3.tb3_section)>0
join (select count(*) as no_of_groups
from t3 inner join t2 on find_in_set(t2.tb2_sector,t3.tb3_section)>0) t4 --no join condition makes a Cartesian join
group by t1.tb1_name
In essence I have two datatables
DataTable 1
PirateShipID PirateShipPreference
123 1
122 2
121 3
And DataTable 2 (which has different named columns, but the data types are the same.
RGPirateShipID PirateShipPreferenceType
123 1
122 1
121 3
I want to grab all records where
PirateShipID == RGPirateShipID && PirateShipePreference != PirateShipPreferenceType
Ideally using Linq as I believe that would be my quickest way of accomplishing this
var idsNotinPirates = from r in DataTable1.AsEnumerable()
//Get all records that don't match on preference
where DataTable2.AsEnumerable().Any(r2 => r["PirateShiptID"] == r2["RGPirateShipID"] && r["PirateShipPreference"] != r2["PirateShipPreferenceType"])
select r;
However, DataTable 1 has about 10k pirateships and Datatable2 has 1 million.
It takes the application a long time to complete the above.
How can i make this more efficient?
I believe you should probably be doing something like this:
var query = from r in DataTable1.AsEnumerable()
join r2 in DataTable2.AsEnumerable() on r["PirateShipID"] equals r2["RGPirateShipID"] into joinedTable
where joinedTable["PirateShipPreference"] != joinedTable["PirateShipPreferenceType"]
select r
I have the following table structure also i have mention my expected output
please help me with query as i dont know much about sql query
Table Structure
Table 1 : Emp Details
FName Id
Pratik 1
Praveen 3
Nilesh 2
Table 1 : JoinigDocument
id DocumentName
1 Leaving
2 Exp letter
3 birth cert
Table 2 : EmployeeJoiningDocument
EmpId JoiningDocumentId
1 1
1 2
3 1
3 2
3 3
2 1
2 3
Expected Output :
FName Id JoiningDocumentId DocumentName
Pratik 1 1 Leaving
Pratik 1 2 Exp letter
Pratik 1 null birth cert
Praveen 3 1 Leaving
Praveen 3 2 Exp letter
Praveen 3 3 birth cert
Nilesh 2 1 Leaving
Nilesh 2 null Exp letter
Nilesh 2 3 birth cert
You can write a query as:
select
A.FName,
A.Id,
B.JoiningDocumentId,
c.DocumentName
from #JoinigDocument C
cross join #EmployeeDetail A
Left join #EmployeeJoiningDocument B on B.EmployeeId = A.id and
B.JoiningDocumentId = C.id
order by A.Id
First cross join JoinigDocument and EmployeeDetail table so that you get all possible combinations of Employee and Documents irrespective of the fact that employee has that Joining Document or not. Then you need to do a left join to retain all these matches and find data corresponding to valid entries in EmployeeJoiningDocument.
Demo
I have the following NHibernate DetatchedCriteria,
return DetachedCriteria.For<MMFund>()
.CreateCriteria<MMFund>(x => x.DataUniverse)
.Add<DataUniverse>(x => x.SiteId == 100)
.SetProjection(LambdaProjection.Property<MMFund>(x => x.FundId));
which is producing the following SQL:
and
this_.ShareClassReturn_ShareClassId in
(
SELECT f.[Fund_ID] as y0_
FROM
dbo.Fund f inner join CAP.DataUniverse du
on f.[Fund_TypeID] = du.[DataUniverse_TypeId]
and f.[Fund_CountryID] = du.[DataUniverse_CountryID]
WHERE fu.[DataUniverse_SiteId] = 100
)
There are many funds in a DataUniverse.
I need to filter this so that I can select only the funds with a country ID of 'ET', so that my query looks as follows:
and
scr.ShareClassReturn_ShareClassId in
(
/* Get funds in universe */
SELECT f.[Fund_ID] as y0_
FROM dbo.Fund f inner join CAP.DataUniverse du
on f.[Fund_TypeID] = du.[DataUniverse_TypeId]
and f.[Fund_CountryID] = 'ET' // these are the guys I need
WHERE du.[DataUniverse_SiteId] = 100
)
However, I'm not sure what I need to do to the DetachedCriteria in order to make this happen. The problem I'm having is that no matter what I do, it's putting the clause in the wrong place, such as
WHERE du.[DataUniverse_SiteId] = 100 and f.Fund_CountryId = 'ET'
when I add the line .Add(Restrictions.Eq("CountryId", "ET")) as follows
return DetachedCriteria.For<MMFund>()
.Add(Restrictions.Eq("CountryId", "ET"))
.CreateCriteria<MMFund>(x => x.DataUniverse)
.Add<DataUniverse>(x => x.SiteId == 100)
.SetProjection(LambdaProjection.Property<MMFund>(x => x.FundId));
or it attempts to filter on the wrong table entirely when I specify that the Restriction should be part of the second .CreateCriteria, such as
return DetachedCriteria.For<MMFund>()
.CreateCriteria<MMFund>(x => x.DataUniverse)
.Add(Restrictions.Eq("CountryId", "ET"))
.Add<DataUniverse>(x => x.SiteId == 100)
.SetProjection(LambdaProjection.Property<MMFund>(x => x.FundId));
which produces this;
WHERE du.[DataUniverse_SiteId] = 100 and du.[DataUniverse_CountryID] = 'ET'
** note - as I'm using the Criteria API, this is actually the Restriction that I'm using:
.Add<MMFund>(f => f.CountryId == "ET")
I used the Restriction terminology because it's more explicit to what I'm trying to achieve. The Criteria API & the other way both produce the exact same results.
Why do you think Where is the wrong place for the filter? That's where filtering happens.
The generated SQL looks sound. You have two tables joined on their common fields. The Where clause is providing the appropriate filtering information. If your preferred SQL statement was in place, you'd have data joined on TypeID alone, not the CountryID.
For example, let's say your Fund table looks like this
TypeID CountryID
1 1
1 2
2 1
2 2
3 1
4 1
And your DataUniverse table is the following
TypeID CountryID
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
4 1
4 2
If you wrote SQL like you desire, you would produce a join based on TypeID and you would filter Fund.CountryID = 1, for example. What would your product look like?
F.TypeID F.CountryID D.TypeID D.CountryID
1 1 1 1
1 1 1 2
1 1 1 3
2 1 2 1
2 1 2 2
2 1 2 3
3 1 3 1
3 1 3 2
4 1 4 1
4 1 4 2
Is that your desired output? Yes, you've filtered Fund.CountryID, but your join was just on TypeID, so you've got all records from DataUniverse with that matching type for each Fund.
With the join on the two fields and the Where filtering the CountryID, the result will be the following
F.TypeID F.CountryID D.TypeID D.CountryID
1 1 1 1
2 1 2 1
3 1 3 1
4 1 4 1
The question is which set of data is the one you expect?