大约有 31,100 项符合查询结果（耗时：0.0600秒） [XML]
Grouping functions (tapply, by, aggregate) and the *apply family
...user-defined function to apply:
# Append ! to string, otherwise increment
myFun <- function(x){
if(is.character(x)){
return(paste(x,"!",sep=""))
}
else{
return(x + 1)
}
}
#A nested list structure
l <- list(a = list(a1 = "Boo", b1 = 2, c1 = "Eeek"),
b = ...
Cast a Double Variable to Decimal
...is better than a silently creating wrong data
– this.myself
Nov 27 '19 at 11:04
add a comment
|
...
What is the best extension for SQLite database files? [closed]
...
In distributable software, I dont want my customers mucking about in the database by themselves. The program reads and writes it all by itself. The only reason for a user to touch the DB file is to take a backup copy. Therefore I have named it whatever_records.d...
Is there any difference between “!=” and “” in Oracle Sql?
...
Interesting! I did not know about the the ^= (saw it myself the first time when I posted the link to the manual). But your point about cached queries is a good one.
– a_horse_with_no_name
May 18 '12 at 10:36
...
Print Var in JsFiddle
How would I print something to the result screen in JsFiddle from my JavaScript. I can't use document.write() , it doesn't allow it, neither print .
...
EOL conversion in notepad ++
For some reason, when I open files from a unix server on my windows machine, they occasionally have Macintosh EOL conversion, and when I edit/save them again they don't work properly on the unix server. I only use notepad ++ to edit files from this unix server, so is there a way to create a macro t...
How can I check MySQL engine type for a specific table?
My MySQL database contains several tables using different storage engines
(specifically myisam and innodb). How can I find out which tables are
using which engine?
...
www-data permissions?
...o). I'm afraid to change the permissions to 777 in case some other user on my machine (or a hacker) attempts to modify files in that directory. How do I only allow access for myself and Apache's www-data?
...
Laravel Redirect Back with() Message
...
@AndrewSavetchuk -- it isn't my comment. Another SO user had edited the answer when he should just have left a comment here or created his own answer.
– Michael
Aug 1 '19 at 9:37
...
Android phone orientation overview including compass
I've been trying to get my head around the Android orientation sensors for a while.
I thought I understood it. Then I realised I didn't. Now I think (hope) I have a better feeling for it again but I am still not 100%. I will try and explain my patchy understanding of it and hopefully people will be ...