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How to have an automatic timestamp in SQLite?
....200');
INSERT INTO my_table(name) VALUES('test3');
This is the result:
SELECT * FROM my_table;
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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 ...
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...
Python Pandas merge only certain columns
...
You can use .loc to select the specific columns with all rows and then pull that. An example is below:
pandas.merge(dataframe1, dataframe2.iloc[:, [0:5]], how='left', on='key')
In this example, you are merging dataframe1 and dataframe2. You h...
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 | ≥...
How do I test which class an object is in Objective-C?
...objective-c runtime api:
#import <objc/runtime.h>
/* ... */
const char* className = class_getName([yourObject class]);
NSLog(@"yourObject is a: %s", className);
EDIT: In Swift
if touch.view is UIPickerView {
// touch.view is of type UIPickerView
}
...
Get table column names in MySQL?
...DESCRIBE my_table;
Or in newer versions you can use INFORMATION_SCHEMA:
SELECT COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_SCHEMA = 'my_database' AND TABLE_NAME = 'my_table';
Or you can use SHOW COLUMNS:
SHOW COLUMNS FROM my_table;
...
Remove Select arrow on IE
I have select element, i want to remove the arrow, then i can add other icon..
i can do that for Firefox Safari and Chrome,
but this didn't work on IE9 .
...
What's the difference between TRUNCATE and DELETE in SQL
...tranTest | DELETE FROM tranTest |
| SELECT * FROM tranTest | SELECT * FROM tranTest |
| ROLLBACK | ROLLBACK |
| SELECT * FROM tranTest | SELE...
Query for array elements inside JSON type
...src":"bar.png"}]
, "background":"background.png"}'::json)
)
SELECT *
FROM reports r, json_array_elements(r.data#>'{objects}') obj
WHERE obj->>'src' = 'foo.png';
The CTE (WITH query) just substitutes for a table reports.
Or, equivalent for just a single level of nesting:
SE...