大约有 40,000 项符合查询结果（耗时：0.0295秒） [XML]
How to find elements by class
...
CSS selectors
single class first match
soup.select_one('.stylelistrow')
list of matches
soup.select('.stylelistrow')
compound class (i.e. AND another class)
soup.select_one('.stylelistrow.otherclassname')
soup.select('.st...
How to sleep for five seconds in a batch file/cmd [duplicate]
...specify the timeout in seconds and the /D parameter to specify the default selection and ignore then selected choice.
The one thing that might be an issue is if the user types one of the choice characters before the timeout period elapses. A partial work-around is to obfuscate the situation -- use ...
LINQ: Select an object and change some properties without creating a new object
.... But here is the expanded LINQ expression example.
var query = someList.Select(x => { x.SomeProp = "foo"; return x; })
What this does is use an anonymous method vs and expression. This allows you to use several statements in one lambda. So you can combine the two operations of setting the ...
Retrieve the maximum length of a VARCHAR column in SQL Server
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Use the built-in functions for length and max on the description column:
SELECT MAX(LEN(DESC)) FROM table_name;
Note that if your table is very large, there can be performance issues.
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SQL RANK() versus ROW_NUMBER()
...he first 3 rows are tied when ordered by ID)
WITH T(StyleID, ID)
AS (SELECT 1,1 UNION ALL
SELECT 1,1 UNION ALL
SELECT 1,1 UNION ALL
SELECT 1,2)
SELECT *,
RANK() OVER(PARTITION BY StyleID ORDER BY ID) AS 'RANK',
ROW_NUMBER() OVER(PARTITION BY Style...
How do I write LINQ's .Skip(1000).Take(100) in pure SQL?
...W_NUMBER function. eg.
USE AdventureWorks;
GO
WITH OrderedOrders AS
(
SELECT SalesOrderID, OrderDate,
ROW_NUMBER() OVER (ORDER BY OrderDate) AS 'RowNumber'
FROM Sales.SalesOrderHeader
)
SELECT *
FROM OrderedOrders
WHERE RowNumber BETWEEN 51 AND 60; --BETWEEN is inclusive
...
Joining three tables using MySQL
...
Simply use:
select s.name "Student", c.name "Course"
from student s, bridge b, course c
where b.sid = s.sid and b.cid = c.cid
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Difference between SelectedItem, SelectedValue and SelectedValuePath
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Their names can be a bit confusing :). Here's a summary:
The SelectedItem property returns the entire object that your list is bound to. So say you've bound a list to a collection of Category objects (with each Category object having Name and ID properties). eg. ObservableCollection&l...
How to determine total number of open/active connections in ms sql server 2005
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This shows the number of connections per each DB:
SELECT
DB_NAME(dbid) as DBName,
COUNT(dbid) as NumberOfConnections,
loginame as LoginName
FROM
sys.sysprocesses
WHERE
dbid > 0
GROUP BY
dbid, loginame
And this gives the total:
SELECT
CO...
App Inventor 2 SQLite 拓展：超流行兼容主流SQL语法的迷你本地数据库引擎...
...原始调用中指定的标签以及新行或更新行的行 ID。
AfterSelect(tag,rowCount,rows)
此事件在异步 Select 调用后触发。
提供原始调用中指定的标签、返回的行数以及结果行数据。
AfterUpdate(tag,rowCount)
此事件在异步 Update 调用后触发。...