大约有 44,000 项符合查询结果(耗时:0.0374秒) [XML]
Get top n records for each group of grouped results
...ould need to specify the group number and add queries for each group:
(
select *
from mytable
where `group` = 1
order by age desc
LIMIT 2
)
UNION ALL
(
select *
from mytable
where `group` = 2
order by age desc
LIMIT 2
)
There are a variety of ways to do this, see this articl...
Add a column to existing table and uniquely number them on MS SQL Server
...ey.
UPDATE MyTable
SET MyTable.MyNewColumn = AutoTable.AutoNum
FROM
(
SELECT MyPrimaryKey,
ROW_NUMBER() OVER (ORDER BY SomeColumn, SomeOtherColumn) AS AutoNum
FROM MyTable
) AutoTable
WHERE MyTable.MyPrimaryKey = AutoTable.MyPrimaryKey
This works in SQL Sever 2005 and later, i.e. ...
Any way to select without causing locking in MySQL?
...s/22-mysql-with-nolock.aspx
in MS SQL Server you would do the following:
SELECT * FROM TABLE_NAME WITH (nolock)
and the MYSQL equivalent is
SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED ;
SELECT * FROM TABLE_NAME ;
SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ ;
EDIT
Mic...
Installing Apple's Network Link Conditioner Tool
...per.apple.com/download/more/?q=Additional%20Tools
Install the dmg file, select hardware from installer
select Network Link conditioner prefpane
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How to detect when cancel is clicked on file input?
...s not exposed to the browser." This is not true if the dialog is closed by selecting a file.
– Trevor
Dec 1 '16 at 22:24
...
Glorified classes in the Java language
...
@aioobe: exactly. Note that you also have int.class, char.class, etc.
– Michael Borgwardt
Aug 11 '10 at 13:19
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UITextField auto-capitalization type - iPhone App
...nspector of the interface builder when you have the appropriate text field selected:
"Capitalization" is the first option in this group, just passed picking the minimum font size for the text field.
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How can I backup a remote SQL Server database to a local drive?
...er to perform a decent backup of your database, even on a remote server:
Select the database you wish to backup and hit next,
In the options it presents to you:
In 2010: under the Table/View Options, change 'Script Data' and 'Script Indexes' to True and hit next,
In 2012: under 'General', change...
difference between Product Backlog Item and Feature in Team Foundation work item types
...n I want to create a new work item, I'm given a list of work item types to select from, among which are "Product Backlog Item" and "Feature".
...
How to perform OR condition in django queryset?
...st_name__startswith='D'
)
leads to
In [5]: str(queryset.query)
Out[5]: 'SELECT "auth_user"."id", "auth_user"."password", "auth_user"."last_login",
"auth_user"."is_superuser", "auth_user"."username", "auth_user"."first_name",
"auth_user"."last_name", "auth_user"."email", "auth_user"."is_staff",
"a...
