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Entity Framework select distinct name
...
Using lambda expression..
var result = EFContext.TestAddresses.Select(m => m.Name).Distinct();
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What columns generally make good indexes?
...earching the results speedily from tables. So it is most important step to select which columns to be indexed. There are two major places where we can consider indexing: columns referenced in the WHERE clause and columns used in JOIN clauses. In short, such columns should be indexed against which yo...
Counting DISTINCT over multiple columns
... function turns the ints into varchars to make the distinct more reliable
SELECT COUNT(DISTINCT (CHECKSUM(DocumentId,DocumentSessionId)) + CHECKSUM(REVERSE(DocumentId),REVERSE(DocumentSessionId)) )
FROM DocumentOutPutItems
...
Set custom HTML5 required field validation message
...he HTML5 "required" functionality to also validate against only whitespace chars being submitted (whereas by default it only validates against an empty string being submitted). So I changed the two lines with if (input.value == "") {, to instead read if (input.value.trim() == "") { - does the trick ...
List the queries running on SQL Server
...will show you the longest running SPIDs on a SQL 2000 or SQL 2005 server:
select
P.spid
, right(convert(varchar,
dateadd(ms, datediff(ms, P.last_batch, getdate()), '1900-01-01'),
121), 12) as 'batch_duration'
, P.program_name
, P.hostname
, P.loginame
from mast...
Random record in ActiveRecord
...he first, all after are still sorted by id). If you need multiple randomly selected records you must use this approach multiple times or use the random order method provided by your database, i.e. Thing.order("RANDOM()").limit(100) for 100 randomly selected entries. (Be aware that it's RANDOM() in P...
What is SELF JOIN and when would you use it? [duplicate]
...et information for both people in one row, you could self join like this:
select e1.EmployeeID,
e1.FirstName,
e1.LastName,
e1.SupervisorID,
e2.FirstName as SupervisorFirstName,
e2.LastName as SupervisorLastName
from Employee e1
left outer join Employee e2 on e1.SupervisorID ...
Accessing inactive union member and undefined behavior?
...object representation of an object of type T is the sequence of N unsigned char objects taken up by
the object of type T, where N equals sizeof(T). The value representation of an object is the set of bits that
hold the value of type T. For trivially copyable types, the value representation is a ...
Split function equivalent in T-SQL?
...AR(2048) = 'Mike/John/Miko/Matt'; DECLARE CaracString NVARCHAR(1) = '/'; SELECT * FROM dbo.FnSplitString (VarString, CaracString)
– fernando yevenes
Feb 8 '19 at 15:57
ad...
WSAAsyncSelect模型 - C/C++ - 清泛网 - 专注C/C++及内核技术
... }
break;
case FD_WRITE:
{
}
break;
case FD_READ:
{
char szText[1024]={0};
if(recv(s,szText,1024,0)==-1)
closesocket(s);
else
{
GetDlgItemText(IDC_EDIT1,strContent);
if(!strContent.IsEmpty())
{
strContent+="\r\n";
}
CString s...