大约有 40,000 项符合查询结果（耗时：0.0238秒） [XML]
What makes a SQL statement sargable?
...non-sargable is to include a field inside a function in the where clause:
SELECT ... FROM ...
WHERE Year(myDate) = 2008
The SQL optimizer can't use an index on myDate, even if one exists. It will literally have to evaluate this function for every row of the table. Much better to use:
WHERE myDat...
Can a C# class inherit attributes from its interface?
...e T : Attribute
{
return GetCustomAttributes( type, typeof( T ), false ).Select( arg => (T)arg ).ToArray();
}
/// <summary>Searches and returns attributes.</summary>
/// <typeparam name="T">The type of attribute to search for.</typeparam>
/// <param name="type">Th...
How to calculate age (in years) based on Date of Birth and getDate()
...low:
try this:
DECLARE @dob datetime
SET @dob='1992-01-09 00:00:00'
SELECT DATEDIFF(hour,@dob,GETDATE())/8766.0 AS AgeYearsDecimal
,CONVERT(int,ROUND(DATEDIFF(hour,@dob,GETDATE())/8766.0,0)) AS AgeYearsIntRound
,DATEDIFF(hour,@dob,GETDATE())/8766 AS AgeYearsIntTrunc
OUTPUT:
Age...
SQL Server query to find all permissions/access for all users in a database
...s the user/role has on an object. Examples could include CONNECT, EXECUTE, SELECT
DELETE, INSERT, ALTER, CONTROL, TAKE OWNERSHIP, VIEW DEFINITION, etc.
This value may not be populated for all roles. Some built in roles have implicit permission
d...
How do I auto size a UIScrollView to fit its content
...
for (UIView *view in self.scrollView.subviews) {
contentRect = CGRectUnion(contentRect, view.frame);
}
self.scrollView.contentSize = contentRect.size;
Swift
let contentRect: CGRect = scrollView.subviews.reduce(into: .zero) { rect, view in
rect = rect.union(view.frame)
}
scrollView.c...
How do I change db schema to dbo
...which will generate a set of ALTER sCHEMA statements for all your talbes:
SELECT 'ALTER SCHEMA dbo TRANSFER ' + TABLE_SCHEMA + '.' + TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = 'jonathan'
You then have to copy and run the statements in query analyzer.
Here's an older script t...
How to export all data from table to an insertable sql format?
... top level of the context menu Thanks to Daniel for the comment to update.
Select generate scripts
Click next
Choose tables
Click next
Click advanced
Scroll to Types of data to script - Called types of data to script in SMSS 2014 Thanks to Ellesedil for commenting
Select data only
Click on 'Ok' to c...
XPath OR operator for different nodes
...
If you want to select only one of two nodes with union operator, you can use this solution:
(//bookstore/book/title | //bookstore/city/zipcode/title)[1]
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Is it possible to GROUP BY multiple columns using MySQL?
Is it possible to GROUP BY more than one column in a MySQL SELECT query? For example:
7 Answers
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How to trim a string in SQL Server before 2017?
...
SELECT LTRIM(RTRIM(Names)) AS Names FROM Customer
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