大约有 48,000 项符合查询结果（耗时：0.0692秒） [XML]
Use '=' or LIKE to compare strings in SQL?
...
To see the performance difference, try this:
SELECT count(*)
FROM master..sysobjects as A
JOIN tempdb..sysobjects as B
on A.name = B.name
SELECT count(*)
FROM master..sysobjects as A
JOIN tempdb..sysobjects as B
on A.name LIKE B.name
Comparing strings with '=' is muc...
PostgreSQL: Difference between text and varchar (character varying)
... article does detailed testing to show that the performance of inserts and selects for all 4 data types are similar. It also takes a detailed look at alternate ways on constraining the length when needed. Function based constraints or domains provide the advantage of instant increase of the length c...
powershell - extract file name and extension
...tated, use the BaseName and Extension properties:
PS C:\> dir *.xlsx | select BaseName,Extension
BaseName Extension
-------- ---------
StackOverflow.com Test Config .xlsx
If you are given the file name as part of string...
jquery input select all on focus
I'm using this code to try and select all of the text in the field when a user focuses on the field. What happens is, it selects all for a second, then its unselected and the typing cursor is left where I clicked...
...
In Eclipse, what can cause Package Explorer “red-x” error-icon when all Java sources compile without
...ers e.g __duplicatefile.java . To fix this, rightclick on the project and select : Show In > Navigator . Then delete the duplicate files with underscore and build your project.
– GraSim
May 29 '15 at 10:28
...
Faster way to develop and test print stylesheets (avoid print preview every time)?
...P (Mac) or Ctrl+Shift+P (Windows, Linux))
2. Start typing Rendering and select Show Rendering.
3. For the Emulate CSS Media dropdown, select print.
UPDATE 29/02/2016
The DevTools docs have moved and the above link provides inaccurate information. The updated docs regarding Media type em...
Generating a random & unique 8 character string using MySQL
...umn:
INSERT INTO vehicles VALUES (blah); -- leaving out the number plate
SELECT @lid:=LAST_INSERT_ID();
UPDATE vehicles SET numberplate=concat(
substring('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789', rand(@seed:=round(rand(@lid)*4294967296))*36+1, 1),
substring('ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'...
Most efficient T-SQL way to pad a varchar on the left to a certain length?
...cely. It will also perform the conversion for you:
declare @n as int = 2
select FORMAT(@n, 'd10') as padWithZeros
Update:
I wanted to test the actual efficiency of the FORMAT function myself. I was quite surprised to find the efficiency was not very good compared to the original answer from Al...
ERROR ITMS-9000: “Redundant Binary Upload. There already exists a binary upload with build version '
...umber just has to be unique (and higher) for each binary that is uploaded (select the Target, then Xcode -> General -> Build, see the picture below).
For example in the image below the build uploaded has version 3.1.4 (3.75 in the older image) and the build number is 1. Thus, after uploading t...
用户反馈ble广播数据收不到 - 用户反馈 - 清泛IT社区，为创新赋能！
...？要是可以的话我就先买个离线版的，在线的太慢了
清泛:
ble 广播用法不常见，也不太安全，目前就之前一个用户反馈要这个功能，应该是成功过的。这块我还没有实地测试，后续我会用硬件测试一下的
MCU&物联网:
我...