大约有 9,859 项符合查询结果（耗时：0.0187秒） [XML]
MySQL - length() vs char_length()
... in two bytes. Or UTF-8, where the number of bytes varies. For example:
select length(_utf8 '€'), char_length(_utf8 '€')
--> 3, 1
As you can see the Euro sign occupies 3 bytes (it's encoded as 0xE282AC in UTF-8) even though it's only one character.
...
Convert Existing Eclipse Project to Maven Project
...mport an existing Eclipse project. Rather, it gives the user an option of selecting dependencies, etc., which may be difficult if the user doesn't have much experience with Maven.
– Kaleb Pederson
Mar 15 '10 at 18:58
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HQL ERROR: Path expected for join
...
select u from UserGroup ug inner join ug.user u
where ug.group_id = :groupId
order by u.lastname
As a named query:
@NamedQuery(
name = "User.findByGroupId",
query =
"SELECT u FROM UserGroup ug " +
"INNER JOIN...
R memory management / cannot allocate vector of size n Mb
...a whole.
To use Readyboost, right click on the drive, go to properties and select 'ReadyBoost' and select 'use this device' radio button and click apply or ok to configure.
How to generate a number of most distinctive colors in R?
...the colorBrewer package (and website). If you want diverging colours, then select diverging on the site. For example,
library(colorBrewer)
brewer.pal(7, "BrBG")
The I want hue web site gives lots of nice palettes. Again, just select the palette that you need. For example, you can get the rgb col...
Convert XLS to CSV on command line
...
The code converts only the active worksheet. To select another worksheet, add the following line after the oExcel.Workbooks.Open line with the desired index of the worksheet (starts at 1): oBook.Worksheets(1).Activate
– humbads
Oct 3...
What is pseudopolynomial time? How does it differ from polynomial time?
...mon intuition for polynomial time is "time O(nk) for some k." For example, selection sort runs in time O(n2), which is polynomial time, while brute-force solving TSP takes time O(n · n!), which isn't polynomial time.
These runtimes all refer to some variable n that tracks the size of the input. Fo...
Sqlite LIMIT / OFFSET query
...< 100000; i++)
{
//first version
timeLimitOffset += SqlDuraction("Select * from table1 order by col1 LIMIT " + (i + 1) + " OFFSET " + (1001 - i) + "");
// second version
timeLimitComma += SqlDuraction("Select * from table1 order by col1 LIMIT " + (1001 - i) + " , " + (i + 1) + "");
}...
SQL Developer is returning only the date, not the time. How do I fix this?
...WOW... this was beautiful. Can't believe I was doing the conversion in the select statement.
– Leniel Maccaferri
Sep 21 '13 at 0:07
16
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Registry Key '…' has value '1.7', but '1.6' is required. Java 1.7 is Installed and the Registry is P
...va Runtime Environment"- On right hand side you will get 4-5 rows . Please select "CurrentVersion" and right Click( select modify option) Change version to "1.7"
Now the magic has been completed
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