How would I convert the SQL statement below into LINQ?
select
kcustnum,
(custsnum + 1),
custartype,
kcustsrch
from
custmast
where
kcustnum = 'cn'
and
custsnum in (
select
max(custsnum)
from
custmast
where
kcustnum = 'cn'
)
As #Dai mention you don't need IN since you use MAX.
What you're looking for:
var res = _context.custmast
.Where(x => x.kcustnum == "cn"
&& x.custsnum == _context.custmast
.Where(y => y.kcustnum == 'cn')
.Max(y => y.custsnum))
.Select(x => new
{
x.kcustnum,
(x.custsnum + 1),
x.custartype,
x.kcustsrch
});
this is my code that does not work:
public ActionResult NameSelect(string customerNumber)
{
var shipto = from n in db.cs_Custmast
.Where(x => x.kcustnum == customerNumber
&& x.custsnum == db.cs_Custmast
.Where(y => y.kcustnum == customerNumber)
.Max(y => y.custsnum))
.Select (n => new CustomersViewModel
{
Account = n.kcustnum,
Suffix = (n.custsnum + 1),
AccountType = n.custartype,
Search = n.kcustsrch
});
return View("_NameSelection", shipto);
}
Related
I wrote a code that EF Core creates an expression for that looks like this:
DbSet<Reception>()
.Include(x => x.Employee)
.Include(x => x.ReceptionSignatures)
.Where(x => x.Employee.FirstName.Contains("mo"))
.Union(DbSet<Reception>()
.Include(x => x.Employee)
.Include(x => x.ReceptionSignatures)
.Where(x => x.Employee.PersonelId.Contains("mo")))
.Union(DbSet<Reception>()
.Include(x => x.Employee)
.Include(x => x.ReceptionSignatures)
.Where(x => x.Employee.LastName.Contains("mo")))
.Union(DbSet<Reception>()
.Include(x => x.Employee)
.Include(x => x.ReceptionSignatures)
.Where(x => x.Employee.NationId.Contains("mo")))
.OrderBy(x => x.Employee.FirstName.CompareTo("mo") == 0 ? 0 : 1)
.Select(r => new ReceptionAllDTO{
ReceptionId = r.Id,
NationId = r.Employee.NationId,
PersonelId = r.Employee.PersonelId,
FirstName = r.Employee.FirstName,
LastName = r.Employee.LastName,
Birthday = r.Employee.Birthday,
RecepDate = r.RecepDate,
Height = r.Height,
Weight = r.Weight,
ReceptionSignatures = r.ReceptionSignatures,
}
)
In Reception entity, I have a relation to Signature like this:
public virtual ICollection<Signature> ReceptionSignatures { get; set; }
but when EF Core wants to create a query for SQL, it throws this exception:
Unable to translate a collection subquery in a projection since either parent or the subquery doesn't project necessary information required to uniquely identify it and correctly generate results on the client side. This can happen when trying to correlate on keyless entity type. This can also happen for some cases of projection before 'Distinct' or some shapes of grouping key in case of 'GroupBy'. These should either contain all key properties of the entity that the operation is applied on, or only contain simple property access expressions.
It seems like you are querying for more data which is really not efficient. Its better to project your required columns using the Select() and then write a Union.
When writing the Union the number of columns Selected must be same as shown below from a code base i wrote 2 weeks ago and which works.
var billPaymentVoucherQuery = _context.Set<BillPaymentVoucher>().AsQueryable();
var billsQuery = _context.Set<Bill>().AsQueryable();
var anon_billsQuery = billsQuery.Where(w => w.InvoiceDate.Date <= filter.AsAtDate.Date)
.Where(w => w.OperationalStatus == OperationalBillStatus.Approved &&
(
w.FinancialStatus == FinancialBillStatus.Pending ||
w.FinancialStatus == FinancialBillStatus.OnHold ||
w.FinancialStatus == FinancialBillStatus.PartiallyApproved ||
w.FinancialStatus == FinancialBillStatus.Approved
))
.Select(s => new
{
VendorName = s.VendorInvoice.Vendor!.Name,
Type = "Bill",
Date = s.InvoiceDate,
Number = Convert.ToString(s.InvoiceNumber),
Amount = s.LineItemTotal + s.VATAmount
}).AsQueryable();
var anon_billPaymentVoucherQuery = billPaymentVoucherQuery
.Where(w => (
w.UpdatedOn.HasValue &&
w.UpdatedOn.Value.Date <= filter.AsAtDate.Date
)
||
(
w.UpdatedOn.HasValue == false &&
w.CreatedOn.Date <= filter.AsAtDate.Date
))
.Where(w => w.BillPaymentVoucherStatus == BillPaymentVoucherStatus.Paid)
.Select(s => new
{
VendorName = s.PaymentApprovedBill.Bill.VendorInvoice.Vendor!.Name,
Type = "Payment",
Date = s.UpdatedOn ?? s.CreatedOn,
Number = Convert.ToString(s.PaymentApprovedBill.Bill.InvoiceNumber + " | " +
s.PaymentVoucherNumber),
Amount = -s.PayAmount
}).AsQueryable();
var unionedQuery = anon_billsQuery.Union(anon_billPaymentVoucherQuery)
.Where(w => string.IsNullOrWhiteSpace(filter.Type) || w.Type == filter.Type);
int pageSize = 2;
bool hasMoreRecords = true;
var transactionData = await unionedQuery.OrderBy(w => w.VendorName)
.ThenBy(w => w.Date)
.Skip((paginator.PageNumber - 1) * pageSize)
.Take(pageSize)
.ToListAsync(token);
select count(distinct LicencePlate) from MT_Vehicle where IsDeleted=0 and CreatedBy = 1
var count = MT_Vehicle.Where(x => x.IsDeleted==0 && x.CreatedBy == 1)
.Select(x => x.LicencePlate)
.Distinct()
.Count();
You can write that as:
var count = db.MT_Vehicle
.Where( v => v.IsDeleted == 0 && v.CreatedBy == 1 )
.Select(v => v.LicencePlate)
.Distinct()
.Count();
Is there any way to search your database for column names or tables in linqpad. Im looking for a similar feature that you can get in SSMS through red gates sql search.
You can get the table and column names from the Linq mapping. The following should dump out the table and column names.
var columns =
(from t in this.Mapping.GetTables()
from dm in t.RowType.DataMembers
where dm.DbType != null
select new
{
TableName = t.RowType.Name ,
TableSqlName = t.TableName,
dm.DbType,
ColumnName = dm.Name,
dm.IsPrimaryKey,
ColumnSqlName = dm.MappedName
}
);
columns.Dump();
So it should be straightforward to filter this query.
If you enable system tables under properties for your connection you can use a query like this (this is for MS SQL but you can probably adapt it to others)
void Main()
{
var text = "ThingToFind";
SearchColumns(text).Dump("Columns: " + text);
SearchModules(text).Dump("Modules: " + text);
}
#region
IEnumerable<dynamic> SearchColumns(string text)
{
return sys
.columns
.Join(sys.objects, o => o.object_id, i => i.object_id, (o, i) => new { Object = i, Column = o })
.Join(sys.types, o => o.Column.user_type_id, i => i.user_type_id, (o, i) => new { o.Column, o.Object, Type = i })
.Where(c => c.Object.type_desc != "INTERNAL_TABLE")
.Where(c => c.Object.type_desc != "SYSTEM_TABLE")
.OrderBy(c => c.Object.type)
.ThenBy(c => c.Object.name)
.Select(c => new { c.Object, c.Column, c.Type, Default = c.Column.default_object_id != 0 ? sys.default_constraints.Single(d => d.object_id == c.Column.default_object_id).definition : null })
.Select(c => new { Table_Type = c.Object.type_desc, Table = c.Object.name, Name = c.Column.name, Type = c.Type.name, Length = c.Column.max_length, Precision = c.Column.precision, Scale = c.Column.scale, Nullable = c.Column.is_nullable, c.Default })
.AsEnumerable()
.Where(c => c.Name.ContainsIgnoreCase(text));
}
IEnumerable<dynamic> SearchModules(string text, bool findRelatedModules = false)
{
var modules = sys
.sql_modules
.AsEnumerable()
.Join(sys.objects, o => o.object_id, i => i.object_id, (o, i) => new { i.name, definition = o.definition.Trim() })
.ToList();
var result = modules
.Where(m => m.name.ContainsIgnoreCase(text) || m.definition.ContainsIgnoreCase(text))
.ToList();
while (findRelatedModules)
{
var add = result
.SelectMany(r => r.definition.Split(" \t\n\r!##$%^&*()-=+[]{};':\",.<>/?\\|`~".ToCharArray(), StringSplitOptions.RemoveEmptyEntries))
.Distinct()
.Where(token => modules.Any(m => m.name.ToLower() == token.ToLower()))
.Where(token => !result.Any(m => m.name.ToLower() == token.ToLower()))
.ToList();
result.AddRange(add.Select(a => modules.Single(m => m.name.ToLower() == a.ToLower())));
findRelatedModules = add.Any();
}
result
.Where(m => !m.definition.ContainsIgnoreCase(m.name))
.Dump("Renamed Modules");
return result.OrderBy(r => r.name);
}
#endregion
public static class StringExtensions
{
public static bool ContainsIgnoreCase(this string source, string toCheck, bool bCaseInsensitive )
{
return source.IndexOf(toCheck, bCaseInsensitive ? StringComparison.OrdinalIgnoreCase : StringComparison.Ordinal) >= 0;
}
}
I have a query below, How can recreate this one to join the tables that will return a list of SurveyProjectNormDTO using NHibernate? Any help please?
using (var session = OpenSession()){
var projectGroupIds = session.Query<ReportingStructureNodeProjectGroups>()
.Where(x => x.NodeID == nodeId);
projectGroupIds.Fetch(x => x.ProjectGroupID).ToFuture();
var projectIds = session.Query<ProjectGroup>().Where(p => projectGroupIds.Contains(p.Id));
projectIds.Fetch(x => x.ProjectID).ToFuture();
var projectNormProjects = session.Query<SurveyProjectNorm>().Where(x => projectIds.Contains(x.SurveyProjectId));
projectNormProjects.Fetch(x => x.ShortLabels).ToFuture();
projectNormProjects.Fetch(x => x.ReportingNames).ToFuture();
projectNormProjects.Fetch(x => x.NormProject).ToFuture();
var response = new List<SurveyProjectNormDTO>();
projectNormProjects.ToList().ForEach(
p =>
{
response.Add(
new SurveyProjectNormDTO { Id = p.Id, ProjectName = p.NormProject.ProjectName, ReportingName = p.ReportingNames.Select(s => s.LocalizedText).FirstOrDefault() });
});
return response;
I am not sure if these let commands will work fine but you can try this. It will do a single hit on the database fetching the properties. Test it and let us know if it works.
var queryResult = (from p in session.Query<SurveyProjectNorm>()
let projectGroupIds = session.Query<ReportingStructureNodeProjectGroups>().Where(x => x.NodeID == nodeId).Select(x => x.Id)
let projectIds = session.Query<ProjectGroup>().Where(x => projectGroupIds.Contains(x.Id)).Select(x => x.Id)
where projectIds.Contains(p.SurveyProjectId)
select p)
.Fetch(x => x.ShortLabels)
.Fetch(x => x.ReportingNames)
.Fetch(x => x.NormProject)
.ToList();
var response = new List<SurveyProjectNormDTO>();
queryResult.ForEach(p =>
response.Add(new SurveyProjectNormDTO {
Id = p.Id,
ProjectName = p.NormProject.ProjectName,
ReportingName = p.ReportingNames.Select(s => s.LocalizedText).FirstOrDefault() }));
return result;
I have three tables. One is the master table: TableA. One table is referenced by TableA called ReferencedTable and lastly a lookup table referenced by ReferencedTable.
I have this query that returns the ten most recent objects as:
TableADTO TableAlias = null;
LookupTableDTO LookupTableAlias = null;
ReferencedDTO ReferencedAlias = null;
dtos = session.QueryOver(() => TableAlias)
.JoinAlias(() => TableAlias.Object, () =>ReferencedAlias)
.JoinAlias(() => ReferencedAlias.ObjectType, () => LookupTableAlias)
.Where(() => ReferencedAlias.PersonId == user.Id &&
(LookupTableAlias.Id != INVOICE_ID ||
LookupTableAlias.Id != FINANCIAL_ID) &&
TableAlias.Status == NEW_STATUS_FLAG &&
ReferencedAlias.ReceivedDate < DateTime.Now)
.Take(10)
.List()
.Select(dto=>
new AbreviatedDTO
{
Id = dto.Referenced.Id,
Field1 = dto.Field1,
Priority = dto.Referenced.Priority,
ReceivedDate = dto.Referenced.ReceivedDate,
Field1 = dto.Referenced.Field1,
Type = dto.Referenced.Lookup.TypeCode,
Status = dto.Status
}).ToList();
This works as expected. However, I thought the the transformation below would work too. It does bring 10 objects but the objects have all default values and are not populated (e.g. AbreviatedDTO.ReceivedDate = DateTime.Minimum). Am I doing something wrong with the QueryOver?
Any help would be appreciated.
Bill N
TableDTO TableAlias = null;
LookupTableDTO LookupTableAlias = null;
ReferencedDTO ReferencedAlias = null;
dtos = session.QueryOver(() => TableAlias)
.JoinAlias(() => TableAlias.Object, () =>ReferencedAlias)
.JoinAlias(() => ReferencedAlias.ObjectType, () => LookupTableAlias)
.Where(() => ReferencedAlias.PersonId == user.Id &&
(LookupTableAlias.Id != INVOICE_ID ||
LookupTableAlias.Id != FINANCIAL_ID) &&
TableAlias.Status == NEW_STATUS_FLAG &&
ReferencedAlias.ReceivedDate < DateTime.Now)
.SelectList(list => list
.Select(x => TableAlias.Field1)
.Select(x => ReferencedAlias.Id)
.Select(x => ReferencedAlias.Field1)
.Select(x => ReferencedAlias.ReceivedDate)
.Select(x => ReferencedAlias.Priority)
.Select(x => LookupTableAlias.TypeCode))
.TransformUsing(Transformers.AliasToBean<AbreviatedDTO>())
.Take(10)
.List<AbreviatedDTO>()
you'll need to define an alias for each selected field same as the propertyname in the resulting dto
AbreviatedDTO alias = null;
// in query
.SelectList(list => list
.Select(() => TableAlias.Field1).WithAlias(() => alias.Field1)