大约有 48,000 项符合查询结果（耗时：0.0826秒） [XML]
SELECT DISTINCT on one column
...nce the OP corrected his samle output (previously had only ONE result row, now has all shown), this is the correct query:
declare @TestData table (ID int, sku char(6), product varchar(15))
insert into @TestData values (1 , 'FOO-23' ,'Orange')
insert into @TestData values (2 , 'BAR-23' ,...
Entity Framework code first unique column
...ength on your model:
[StringLength(450)]
Your model will look like this now in EF CF 6.1+:
public class User
{
public int UserId{get;set;}
[StringLength(450)]
[Index(IsUnique=true)]
public string UserName{get;set;}
}
Update:
if you use Fluent:
public class UserMap : EntityTypeC...
How to find the length of a string in R
... a string (number of characters in a string) without splitting it in R? I know how to find the length of a list but not of a string.
...
Application Crashes With “Internal Error In The .NET Runtime”
...
How did you know they were listed in CorError.h??
– Yeonho
Jun 27 '12 at 6:52
6
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COUNT DISTINCT with CONDITIONS
... The edited query still does not solve the problem - isn't this now working on distinct entryId values rather than distinct tags?
– BrianC
Dec 27 '12 at 1:08
...
How to generate sample XML documents from their DTD or XSD?
...
Do you guys happen to know what Eclipse feature provides this functionality? My "Generate" submenu has "JAXB Classes" as the only item.
– otto.poellath
Mar 10 '11 at 16:27
...
how can you easily check if access is denied for a file in .NET?
... to open it. A change is even more likely if you're in an area where you know you need to check first. Yet strangely enough it will never happen in your testing or development environments, which tend to be fairly static. This makes the problem difficult to track down later and makes it easy for ...
How to check whether a given string is valid JSON in Java
...e option would be to use Jackson library. First import the latest version (now is):
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.7.0</version>
</dependency>
Then, you can...
How to prevent gcc optimizing some statements in C?
... memory stores and loads. One purpose of volatile is to let the compiler know that the memory access has side effects, and therefore must be preserved. In this case, the store has the side effect of causing a page fault, and you want the compiler to preserve the page fault.
This way, the surround...
Remove blue border from css custom-styled button in Chrome
... custom-styled <button> tags. So with CSS, I said: border: none . Now it works perfectly in safari, but in chrome, when I click one of the buttons, it puts an annoying blue border around it. I thought button:active { outline: none } or button:focus { outline:none } would work, but neith...