大约有 30,000 项符合查询结果（耗时：0.0536秒） [XML]
Generate a random number in the range 1 - 10
Since my approach for a test query which I worked on in this question did not work out, I'm trying something else now. Is there a way to tell pg's random() function to get me only numbers between 1 and 10?
...
How to select the row with the maximum value in each group
...
A dplyr solution:
library(dplyr)
ID <- c(1,1,1,2,2,2,2,3,3)
Value <- c(2,3,5,2,5,8,17,3,5)
Event <- c(1,1,2,1,2,1,2,2,2)
group <- data.frame(Subject=ID, pt=Value, Event=Event)
group %>%
group_by(Subject) %>%
summarize(max.pt = max(...
What is the advantage of using REST instead of non-REST HTTP?
...ons about how to use HTTP . I wonder which advantage these conventions provide. Does anyone know?
14 Answers
...
How do I uninstall nodejs installed from pkg (Mac OS X)?
I installed NodeJS from pkg file on my Mac. Now I need to uninstall it. Tell me please how to do it.
I tried to remove files from this list:
...
@ variables in Ruby on Rails
... and title ? Since both of them can be variable names. Also, how do I decide which kind of variable I should use? With @ or not?
...
OpenSSL: PEM routines:PEM_read_bio:no start line:pem_lib.c:703:Expecting: TRUSTED CERTIFICATE [close
I need a hash-name for file for posting in Stunnel's CApath directory. I have got some certs in this directory and they are working well. Also, I have a server sert and server key:
...
What 'additional configuration' is necessary to reference a .NET 2.0 mixed mode assembly in a .NET 4
...r to use a CLR 2.0 mixed mode assembly, you need to modify your App.Config file to include:
<?xml version="1.0"?><configuration> <startup useLegacyV2RuntimeActivationPolicy="true"> <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/> </startup></...
Export and Import all MySQL databases at one time
...
Other solution:
It backs up each database into a different file
#!/bin/bash
USER="zend"
PASSWORD=""
#OUTPUT="/Users/rabino/DBs"
#rm "$OUTPUTDIR/*gz" > /dev/null 2>&1
databases=`mysql -u $USER -p$PASSWORD -e "SHOW DATABASES;" | tr -d "| " | grep -v Database`
for db in $...
MySQL Select all columns from one table and some from another table
....
SELECT table1.*, table2.col1, table2.col3 FROM table1 JOIN table2 USING(id)
share
|
improve this answer
|
follow
|
...
How do I get PHP errors to display?
I have checked my PHP ini file ( php.ini ) and display_errors is set and also error reporting is E_ALL . I have restarted my Apache webserver.
...