大约有 23,000 项符合查询结果（耗时：0.0493秒） [XML]
Update or Insert (multiple rows and columns) from subquery in PostgreSQL
... perfect. this works best wherein you need to pick a subset based on a condition involving the updated table itself.
– mythicalcoder
Dec 28 '17 at 9:06
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Detecting iOS / Android Operating system
...erating system (Apple/Android/Other[not supported]) and modify my elements based on that value.
9 Answers
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How to efficiently count the number of keys/properties of an object in JavaScript?
...able
Cons - Memory overhead due to the creation of the array.
2. Library-based solutions
Many library-based examples elsewhere in this topic are useful idioms in the context of their library. From a performance viewpoint, however, there is nothing to gain compared to a perfect no-library code sin...
bash: mkvirtualenv: command not found
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This answer was based on installing virtualenvwrapper with pip, which is what I prefer doing.
– Mike Pennington
Jul 31 '16 at 20:43
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JNI converting jstring to char *
...StringUTFChars(javaString, nativeString);
Can fix this errors:
1.error: base operand of '->' has non-pointer type 'JNIEnv {aka _JNIEnv}'
2.error: no matching function for call to '_JNIEnv::GetStringUTFChars(JNIEnv*&, _jstring*&, bool)'
3.error: no matching function for call to '_JNIE...
How can I get pg_dump to authenticate properly
....pgpass and neither of these two will allow me to authenticate to the database. I have chmod 'd .pgpass to appropriate permissions and also tried:
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How to use a variable to specify column name in ggplot
...string that the variable contains, using sym()(which is almost the same as base aliases as.name() / as.symbol()), and unquote it using !!
Simulating OP's data we can do :
library(tidyverse)
rates.by.groups <- data.frame(
name = LETTERS[1:3],
rate = 1:3,
mjr = LETTERS[c(4,4,5)],
gender =...
How to list the files inside a JAR file?
...it outside your VM. Besides even inside your own application, your locking based on filenames can be easily bypassed. With this things it is better to rely on OS synchronization mechanisms, like file locking.
– Espinosa
Apr 5 '17 at 9:27
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Angular ng-if=“” with multiple arguments
...re the two dots in front? Shouldn't it work without them and the brackets? Based on javaCity's example, this doesn't even work plnkr.co/edit/qdIysgbxtEUVB2WMJa1i?p=preview
– Stefan
May 31 '19 at 12:04
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Using socket.io in Express 4 and express-generator's /bin/www
...(.....)
var io = require('socket.io').listen(server);
require('../sockets/base')(io);
so now I create the ../sockets/base.js file and put this little fellow inside it:
module.exports = function (io) { // io stuff here... io.on('conection..... }
Yeah! Now it works... So i guess i really had no ...