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Why is using the rails default_scope often recommend against?
...ate) posts. So far so good.
2.1.1 :001 > Post.all
Post Load (0.2ms) SELECT "posts".* FROM "posts" WHERE "posts"."published" = 't'
Well this is pretty much what we expect. Now lets try:
2.1.1 :004 > Post.new
=> #<Post id: nil, title: nil, published: true, created_at: nil, update...
What is the difference between Left, Right, Outer and Inner Joins?
...ow you begin your query impacts the outcome of the join type. For example, SELECT * FROM students RIGHT OUTER JOIN lockers... would result in a different outcome than SELECT * FROM lockers RIGHT OUTER JOIN students.... Great answer, but would love to see it updated with complete SQL queries
...
How to track down a “double free or corruption” error
...debug it.
#include<stdio.h>
#include<stdlib.h>
int main()
{
char *x = malloc(100);
free(x);
free(x);
return 0;
}
[sand@PS-CNTOS-64-S11 testbox]$ vim t1.c
[sand@PS-CNTOS-64-S11 testbox]$ cc -g t1.c -o t1
[sand@PS-CNTOS-64-S11 testbox]$ ./t1
*** glibc detected *** ./t1: double free ...
Use didSelectRowAtIndexPath or prepareForSegue method for UITableView?
... I'll have to pass a couple objects to the detail view. But do I use didSelectRowAtIndex or -(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender ?
...
How does one reorder columns in a data frame?
...
You can also use the subset function:
data <- subset(data, select=c(3,2,1))
You should better use the [] operator as in the other answers, but it may be useful to know that you can do a subset and a column reorder operation in a single command.
Update:
You can also use the select...
What does “zend_mm_heap corrupted” mean
...#include <stdlib.h>
int main(void) {
void **mem = malloc(sizeof(char)*3);
void *ptr;
/* read past end */
ptr = (char*) mem[5];
/* write past end */
memcpy(mem[5], "whatever", sizeof("whatever"));
/* free invalid pointer */
free((void*) mem[3]);
retur...
Renew Provisioning Profile
...gn).
I discovered that if I change something on the screen (in my case, I selected a previously
unused device), "Submit" darkens (becomes available).
Click on "Submit".
You're quietly (another UI problem :) taken back to the prior page, and the
"Download" and "Edit" buttons are gone, and the status...
HTML5 canvas ctx.fillText won't do line breaks?
...
If you just want to take care of the newline chars in the text you could simulate it by splitting the text at the newlines and calling multiple times the fillText()
Something like http://jsfiddle.net/BaG4J/1/
var c = document.getElementById('c').getContext('2d');
...
Are the shift operators () arithmetic or logical in C?
... of i, after integer promotion, be T. Assuming n to be in [0, sizeof(i) * CHAR_BIT) — undefined otherwise — we've these cases:
| Direction | Type | Value (i) | Result |
| ---------- | -------- | --------- | ------------------------ |
| Right (>>) | unsigned | ≥...
HTML input file selection event not firing upon selecting the same file
Is there any chance to detect every file selection the user made for an HTML input of type file element?
7 Answers
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