Hi can someone help me how best we can use whereif in LINQ
IQueryable<Employee> empQuery;
if (empId == "")
{
empQuery = dbContext.Emps
.Include(x => x.Name)
.Include(x => x.Code)
.Where(x => x.Id == empId);
}
else
{
empQuery = dbContext.Emps
.Include(x => x.Name)
.Include(x => x.Code);
}
I think we can make this query very simple by using whereif right? Can someone help me how to make this query simple by using whereif? Instead of check if (empid == "") ?
Is it possible?
I assume "whereif" is supposed to be this extension method. You can't use that, because it operates on an IEnumerable<T> and not on a IQueryable<T>. The result would be that you would request your complete employees table from the database and perform the filtering in memory in your application. That's not what you want. You can, however, use the conditional operator to achieve this:
var empQuery = dbContext.Emps
.Include(x => x.Name)
.Include(x => x.Code)
.Where(x => empId == "" ? true : x.Id == empId);
Please note that this assumes that you actually meant if(empId != "") in your sample code. If you didn't mean this, switch the second and third operand around:
.Where(x => empId == "" ? x.Id == empId : true);
Having said this, you certainly can create the same extension method for IQueryable<T>. It looks nearly the same, just has IEnumerable<T> replaced with IQueryable<T> and the predicate changed to an expression:
public static IQueryable<TSource> WhereIf<TSource>(
this IQueryable<TSource> source,
bool condition,
Expression<Func<TSource, bool>> predicate)
{
if (condition)
return source.Where(predicate);
else
return source;
}
I believe you want filtering by empId if it is not empty. Simple OR operator will do the job:
IQueryable<Employee> empQuery = dbContext.Emps
.Include(x => x.Name)
.Include(x => x.Code)
.Where(x => empId == "" || x.Id == empId);
Also you can build query dynamically:
IQueryable<Employee> empQuery = dbContext.Emps
.Include(x => x.Name)
.Include(x => x.Code);
if (empId != "")
empQuery = empQuery.Where(x => x.Id == empId);
.Where(x => x.Id == empId);
Doesn't make sense if the value is '""' - what do you expect it to return?
var query = (from items in dbContext.Emps
where items.Id == empId
select new {
Name = items.Name,
Code = items.Code
}).ToList();
Related
I have flat collection of the following data (IQueryable<Article>) which was obtained by querying DB:
ArticleId
LanguageName
ArticleText
ExtraData1
ExtraData2
1
English
EngText1
Something1
Something2
1
English
EngText2
Another1
Another2
1
French
FraText1
Blabla1
2
English
EngText2
Ololo1
Blabla2
2
German
GerText1
Naturlisch2
Now I need to fill the IQueryable<AgregatedArticle>: the idea is grouping by ArticleId and putting repeating data into nested list:
public class AgregatedArticle {
public int ArticleId { get; set; }
public List<Data> ArticleTexts { get; set; }
public class Data {
public string LanguageName { get; set; }
public string ArticleText { get; set; }
}
}
Unfortunately, I cannot make it: I am getting various EfCore5 translation errors and don't know: if it's me or EfCore5 bugs or limitations. I wasted 3 days trying different approaches. Please help - I was unable to find suitable examples in Internet. The problem comes up when I try to fill ArticleTexts property.
Here is the simplified example:
private async Task<IQueryable<LawArticleAggregated>> GetLawArticlesGroupedById(DbSet<LawArticleDetail> dbSet, string userContentLangRestriction = null)
{
var dbContext = await GetDbContextAsync();
var articlesQuery =
(from articleIds in dbSet.Select(x => x.ArticleId).Distinct()
from articlesPerId in dbSet
.Where(x => x.ArticleId == articleIds.ArticleId)
join askedL in dbContext.Langs
.Where(l => l.LanguageCode == userContentLangRestriction)
on
articlesPerId.LanguageCode
equals
askedL.StringValue
into askedLanguages
from askedLawLanguage in askedLanguages.DefaultIfEmpty()
join fallbackL in dbContext.Langs
.Where(l => l.LanguageCode == CoreConstants.LanguageCodes.English)
on
articlesPerId.LanguageCode
equals
fallbackL.StringValue
into fallbackLanguages
from fallbackLanguage in fallbackLanguages.DefaultIfEmpty()
select new
{
ArticleId = articleIds.ArticleId,
ArticleText = articlesPerId.ArticleText,
LanguageName = askedLawLanguage.ShortName ?? fallbackLanguage.ShortName
})
.OrderBy(x => x.ArticleId).ThenBy(x => x.LanguageName).ThenBy(x => x.ArticleText);
await articlesQuery.LoadAsync();
var aggregatedArticleData = articlesQuery.Select(x => new
{
ArticleId = x.ArticleId,
ArticleText = x.ArticleText,
LanguageName = x.LanguageName
});
var aggregatedArticles = articlesQuery.Select(x => x.ArticleId).Distinct().Select(x => new ArticleAggregated
{
ArticleId = x.ArticleId,
ArticleTexts = aggregatedArticleData.Where(a => a.ArticleId == x.ArticleId)
.Select(x => new LawArticleAggregated.Data
{
ArticleText = x.ArticleText,
LanguageName = x.LanguageName
}).ToList()
});
return aggregatedArticles;
}
For this specific code the exception is as follows:
Unable to translate collection subquery in projection since the parent
query doesn't project key columns of all of it's tables which are
required to generate results on client side. This can happen when
trying to correlate on keyless entity or when using 'Distinct' or
'GroupBy' operations without projecting all of the key columns.
I think I have reverse engineered your query. Big difference that we cannot return IQueryable from this funcrtio, but prepared IEnumerable. So if you have pagination later, better to pass page info into function parameters.
private async Task<IEnumerable<LawArticleAggregated>> GetLawArticlesGroupedById(DbSet<LawArticleDetail> dbSet, string userContentLangRestriction = null)
{
var dbContext = await GetDbContextAsync();
var articlesQuery =
from article in dbSet
from askedLawLanguage in dbContext.Langs
.Where(askedLawLanguage => askedLawLanguage.LanguageCode == userContentLangRestriction && article.LanguageCode == askedLawLanguage.StringValue)
.DefaultIfEmpty()
from fallbackLanguage in dbContext.Langs
.Where(fallbackLanguage => fallbackLanguage.LanguageCode == CoreConstants.LanguageCodes.English && article.LanguageCode == fallbackLanguage.StringValue)
.DefaultIfEmpty()
select new
{
ArticleId = article.ArticleId,
ArticleText = article.ArticleText,
LanguageName = askedLawLanguage.ShortName ?? fallbackLanguage.ShortName
};
articlesQuery = articlesQuery
.OrderBy(x => x.ArticleId)
.ThenBy(x => x.LanguageName)
.ThenBy(x => x.ArticleText);
var loaded = await articlesQuery.ToListAsync();
// group on the client side
var aggregatedArticles = loaded.GroupBy(x => x.ArticleId)
.Select(g => new ArticleAggregated
{
ArticleId = g.Key,
ArticleTexts = g.Select(x => new LawArticleAggregated.Data
{
ArticleText = x.ArticleText,
LanguageName = x.LanguageName
}).ToList()
});
return aggregatedArticles;
}
I ended up with the following implementation (I show it "as is", without simplification from the first message to demonstrate the approach, slightly modified from the initial variant to use proper paging):
private async Task<IEnumerable<LawArticleAggregated>> GetLawArticlesGroupedByIdListAsync(
DbSet<LawArticleDetail> dbSet,
Expression<Func<IQueryable<LawArticleDetail>, IQueryable<LawArticleDetail>>> filterFunc,
int skipCount,
int maxResultCount,
string userContentLangRestriction = null,
CancellationToken cancellationToken = default
)
{
var dbContext = await GetDbContextAsync();
var articlesQuery =
(from articleIds in filterFunc.Compile().Invoke(dbSet).Select(x => new { x.TenantId, x.LawArticleId })
.Distinct().OrderBy(x => x.TenantId).OrderByDescending(x => x.LawArticleId).Skip(skipCount).Take(maxResultCount)
from articlesPerId in dbSet
.Where(x => x.TenantId == articleIds.TenantId && x.LawArticleId == articleIds.LawArticleId)
join askedL in dbContext.FixCodeValues
.Where(l =>
l.DomainId == CoreConstants.Domains.CENTRAL_TOOLS
&& l.CodeName == CoreConstants.FieldTypes.LANGUAGE
&& l.LanguageCode == userContentLangRestriction)
on
articlesPerId.LanguageCode
equals
askedL.StringValue
into askedLanguages
from askedLawLanguage in askedLanguages.DefaultIfEmpty()
join fallbackL in dbContext.FixCodeValues
.Where(l =>
l.DomainId == CoreConstants.Domains.CENTRAL_TOOLS
&& l.CodeName == CoreConstants.FieldTypes.LANGUAGE
&& l.LanguageCode == CoreConstants.LanguageCodes.English)
on
articlesPerId.LanguageCode
equals
fallbackL.StringValue
into fallbackLanguages
from fallbackLanguage in fallbackLanguages.DefaultIfEmpty()
select new
{
TenantId = articleIds.TenantId,
LawArticleId = articleIds.LawArticleId,
Shortcut = articlesPerId.Shortcut,
ArticleText = articlesPerId.ArticleText,
LanguageName = askedLawLanguage.ShortName ?? fallbackLanguage.ShortName
})
.OrderBy(x => x.TenantId).ThenByDescending(x => x.LawArticleId).ThenBy(x => x.Shortcut).ThenBy(x => x.LanguageName).ThenBy(x => x.ArticleText);
var articleList = await articlesQuery.ToListAsync(cancellationToken);
var aggregatedArticles = articleList.GroupBy(x => new { x.TenantId, x.LawArticleId })
.Select(g => new LawArticleAggregated
{
TenantId = g.Key.TenantId,
LawArticleId = g.Key.LawArticleId,
ArticleTexts = g.Select(x => new LawArticleAggregated.Data
{
Shortcut = x.Shortcut,
ArticleText = x.ArticleText,
LanguageName = x.LanguageName
}).ToList()
});
return aggregatedArticles;
}
private async Task<long> GetLawArticlesGroupedByIdCountAsync(
DbSet<LawArticleDetail> dbSet,
Expression<Func<IQueryable<LawArticleDetail>, IQueryable<LawArticleDetail>>> filterFunc,
CancellationToken cancellationToken = default
)
{
return await filterFunc.Compile().Invoke(dbSet).GroupBy(x => new { x.TenantId, x.LawArticleId }).LongCountAsync(cancellationToken);
}
I cannot get the following to work properly. I want to search my database using more than 2 conditions where it will be possible to search only on one, two or all three, thus narrowing the search. At the moment, I can only get it to work with one condition at a time, and it only evaluates the first condition when having more than 3.
How can I Include more than 2 conditions? I have tried several proposed solutions from other sources, that uses if statements and where clauses, but so far none of them have worked.
This is my controller
public IActionResult Index(string searchString, int searchProject, string searchTitel)
{
var Projektdokumenter = from p in _context.ProjekterDokutypeDokuundertype
.Include(p => p.Dokumenttype)
.Include(p => p.Dokuundertype)
.Include(p => p.Forfatter)
.Include(p => p.P)
.Include(p => p.Sprog)
select p;
if (!String.IsNullOrEmpty(searchString) ^ searchProject != null ^ !String.IsNullOrEmpty(searchTitel))
{
if (!String.IsNullOrEmpty(searchString))
{
var c = Projektdokumenter.Where(p => p.Forfatter.Initialer.Contains(searchString)).ToList();
return View(c);
}
{
if (searchProject != 0)
{
var d = Projektdokumenter.Where(p => p.P.ProjektId.Equals(searchProject)).ToList();
return View(d);
}
{
if(!String.IsNullOrEmpty(searchTitel))
{
var f = Projektdokumenter.Where(p => p.Titel.Contains(searchTitel)).ToList();
return View(f);
}
}
}
}
var e = Projektdokumenter.Where(c.Contains(searchString) && p.P.ProjektId.Equals(searchProject) && p.Titel.Contains(searchTitel)).ToList();
return View(e);
}
IQueryable can be combined, so just write in native way:
{
var query = _context.ProjekterDokutypeDokuundertype
.Include(p => p.Dokumenttype)
.Include(p => p.Dokuundertype)
.Include(p => p.Forfatter)
.Include(p => p.P)
.Include(p => p.Sprog)
.AsQueryable();
if (!string.IsNullOrEmpty(searchString))
{
query = query.Where(p => p.Forfatter.Initialer.Contains(searchString));
}
if (searchProject != 0)
{
query = query.Where(p => p.P.ProjektId == searchProject);
}
if (!string.IsNullOrEmpty(searchTitel))
{
query = query.Where(p => p.Titel.Contains(searchTitel))
}
return View(query.ToList());
}
We are trying to exclude certain data from our queries based on a condition, but we can't seem to get it right. Our current code looks like this:
var PullData = _context.RequestInformation.Include(x => x.RequestMinistry)
.Include(x => x.RequestApps)
.ThenInclude(x => x.RequestAppDataChoices)
.Where(x => x.RequestStatus != "Cancelled With Reason")
.Where(y => y.RequestApps.SelectMany(x => x.RequestAppDataChoices)
.Where(s => s.AppDataChoiceDl.Contains(groupName))
.Where(a => a.RequestApps.AppProvisioningCompleteTime != null)
.Where(aa => aa.RequestApps.AppTeamCompleteTime == null)
.Where(ab => !ab.RequestApps.AppStatus.Contains("Rejected")).Any());
This is fine as long as we are trying to pull all of the "RequestApps" with each set of "RequestInformation", however if we want to pull just specific applications based on conditions, it doesn't work. We want to only show the request apps based on the the conditions above (The appdatachoicedl contains "groupname", the completetime != null while the other completetime IS null, and that the status is not rejected), but instead, we are getting all the request information that matches those conditions.
I tried something like this, but it still doesn't quite give me the results I need. It gives me random blank results as well:
var PullDataV2 = from reqInfo in _context.RequestInformation
join RA in _context.RequestApps on reqInfo.ReqNum equals RA.ReqNum
join RADC in _context.RequestAppDataChoices on RA.PkId equals RADC.RequestAppsId
where RADC.AppDataChoiceDl == groupName
select new RequestInformation()
{
ProvisioningCompleteTime = reqInfo.ProvisioningCompleteTime,
RequestMinistry = reqInfo.RequestMinistry,
RequestApps = reqInfo.RequestApps,
UserFirstName = reqInfo.UserFirstName,
UserLastName = reqInfo.UserLastName,
SubmitterFirstName = reqInfo.SubmitterFirstName,
SubmitterLastName = reqInfo.SubmitterLastName,
RequestStatus = reqInfo.RequestStatus
};
I hope I'm making sense here - I only want the requestapps based on the conditions, not all the request information that is those conditions. RequestApps is a part of the RequestInformation class.
Edit:
Piggybacking off of Roberts comments, I modified his code to look like this, but I am struggling with the last line - I need to be able to make sure that "AppDataChoiceDL" which is a member of RequestAppDataChoices (which is a member of RequestApps) is equal to groupName
var PullData = _context.RequestInformation.Include(x => x.RequestMinistry)
.Include(x => x.RequestApps)
.ThenInclude(x => x.RequestAppDataChoices)
.Where(x => x.RequestStatus != "Cancelled With Reason")
.Where(x => x.RequestApps.SelectMany(app => app.RequestAppDataChoices)
.Where(a => a.AppDataChoiceDl.Contains(groupName))
.Where(b => b.RequestApps.AppProvisioningCompleteTime != null)
.Where(c => c.RequestApps.AppTeamCompleteTime == null)
.Any(n => !n.RequestApps.AppStatus.Contains("Rejected"))).Select(reqInfo => new RequestInformation
{
ProvisioningCompleteTime = reqInfo.ProvisioningCompleteTime,
RequestMinistry = reqInfo.RequestMinistry,
UserFirstName = reqInfo.UserFirstName,
UserLastName = reqInfo.UserLastName,
SubmitterFirstName = reqInfo.SubmitterFirstName,
SubmitterLastName = reqInfo.SubmitterLastName,
RequestStatus = reqInfo.RequestStatus,
RequestApps = reqInfo.RequestApps
.Where(a => a.AppProvisioningCompleteTime != null)
.Where(b => b.AppTeamCompleteTime == null)
.Where(x => !x.AppStatus.Contains("Rejected"))
.Where(b => b.RequestAppDataChoices.Where(a => a.AppDataChoiceDl == groupName))
});
This throws an error not being able to convert IENUmerable to bool.. maybe I'm selecting my RequestAppDataChoices wrong?
This assumes you have a RequestInformationDto class that closely resembles your RequestInformation class:
var PullData = _context.RequestInformation.Include(x => x.RequestMinistry)
.Include(x => x.RequestApps)
.ThenInclude(x => x.RequestAppDataChoices)
.Where(x => x.RequestStatus != "Cancelled With Reason")
.Where(x => x.RequestApps.SelectMany(app => app.RequestAppDataChoices)
.Where(x => x.AppDataChoiceDl.Contains(groupName))
.Where(x => x.RequestApps.AppProvisioningCompleteTime != null)
.Where(x => x.RequestApps.AppTeamCompleteTime == null)
.Where(x => !x.RequestApps.AppStatus.Contains("Rejected")).Any())
.Select(reqInfo => new RequestInformationDto {
ProvisioningCompleteTime = reqInfo.ProvisioningCompleteTime,
RequestMinistry = reqInfo.RequestMinistry,
RequestApps = reqInfo.RequestApps
.Where(app => app.AppProvisioningCompleteTime != null)
.Where(app => app.AppTeamCompleteTime == null)
.Where(app => !app.AppStatus.Contains("Rejected")).Any())
.ToList()
UserFirstName = reqInfo.UserFirstName,
UserLastName = reqInfo.UserLastName,
SubmitterFirstName = reqInfo.SubmitterFirstName,
SubmitterLastName = reqInfo.SubmitterLastName,
RequestStatus = reqInfo.RequestStatus
});
I just noticed this part of your query, which should probably be reworked (or removed) as well:
.Where(x => x.RequestApps.SelectMany(app => app.RequestAppDataChoices)
.Where(x => x.AppDataChoiceDl.Contains(groupName))
.Where(x => x.RequestApps.AppProvisioningCompleteTime != null)
.Where(x => x.RequestApps.AppTeamCompleteTime == null)
.Where(x => !x.RequestApps.AppStatus.Contains("Rejected")).Any())
With Robert McKee's help, I was able to come up with this, that does work:
var PullData = _context.RequestInformation.Include(x => x.RequestMinistry)
.Include(x => x.RequestApps)
.ThenInclude(x => x.RequestAppDataChoices)
.Where(x => x.RequestStatus != "Cancelled With Reason")
.Where(x => x.RequestApps.SelectMany(app => app.RequestAppDataChoices)
.Where(a => a.AppDataChoiceDl.Contains(groupName))
.Where(b => b.RequestApps.AppProvisioningCompleteTime != null)
.Where(c => c.RequestApps.AppTeamCompleteTime == null)
.Any(n => !n.RequestApps.AppStatus.Contains("Rejected"))).Select(reqInfo => new RequestInformation
{
ProvisioningCompleteTime = reqInfo.ProvisioningCompleteTime,
RequestMinistry = reqInfo.RequestMinistry,
UserFirstName = reqInfo.UserFirstName,
UserLastName = reqInfo.UserLastName,
SubmitterFirstName = reqInfo.SubmitterFirstName,
SubmitterLastName = reqInfo.SubmitterLastName,
RequestStatus = reqInfo.RequestStatus,
RequestApps = reqInfo.RequestApps
.Where(a => a.AppProvisioningCompleteTime != null)
.Where(b => b.AppTeamCompleteTime == null)
.Where(x => !x.AppStatus.Contains("Rejected"))
.Where(b => b.RequestAppDataChoices.Any(a => a.AppDataChoiceDl == groupName)).ToList()
});
Good day:
I'm trying to achieve a dynamic Bool Query. Example...
QueryContainer addressQuery = null;
QueryContainer typeQuery = null;
BoolQueryDescriptor <Facility> boolQuery = new BoolQueryDescriptor<Facility>();
QueryContainerDescriptor<Facility> sh = new QueryContainerDescriptor<Facility>();
SearchDescriptor<Facility> mainSh = new SearchDescriptor<Facility>();
if (search.searchTerm != null)
{
addressQuery = sh.Term(f => f.Address, search.searchTerm) ||
sh.Match(m => m.Field(f => f.Address).Query(search.searchTerm) ) ||
sh.Term(f => f.ZipCode, search.searchTerm) ||
sh.Match(m => m.Field(f => f.State).Query(search.searchTerm));
boolQuery = boolQuery.Should(b => addressQuery);
}
if (search.type != null) {
typeQuery = sh.Term(f => f.Types.First(), search.type);
boolQuery = boolQuery.Must(b => typeQuery && addressQuery);
}
if (boolQuery != null)
{
mainSh = mainSh.Query(q => q.Bool(b => boolQuery));
request = await this._elasticClient.SearchAsync<Facility>(s => mainSh.Size(search.size));
}
This query is turning into a OR between AddressQuery and TypeQuery however, I'd like to achieve an And condition between both query. Effectively making the query dynamic. Is this possible? Example: dynamic addressQuery && typeQuery.
Thanks.
Fire it out..you can && or || query containers...sorter like:
queryContainer1=queryContainer1 && queryContainer2
Then .bool(b => b(queryContainer1)).
I have the following code that gives me a an array in an autocomplete extender:
return autocomplete.tblAutoCompletes
.Where(p => p.MemberId == memberid && p.LocationId == locationid && p.ACItem.Contains(prefixText))
.OrderBy(p => p.ACItem)
.Select(p => p.ACItem)
.Take(count)
.ToArray();
However, I may need to programmatically exclude certain items from the array.
How would I do that? So for example, ACItem list = Product1, Product2, Product3.
How would I amend the code so that Product2 is excluded?
autocomplete.tblAutoCompletes
.Where(p => p.MemberId == memberid && p.LocationId == locationid && p.ACItem.Contains(prefixText))
.OrderBy(p => p.ACItem)
.Select(p => p.ACItem)
.Take(count)
.Where(p => p != Product1)
.Select(p => p)
.ToArray();