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Error 1022 - Can't write; duplicate key in table
...ere the constraints are currently in use you can use the following query:
SELECT `TABLE_SCHEMA`, `TABLE_NAME`
FROM `information_schema`.`KEY_COLUMN_USAGE`
WHERE `CONSTRAINT_NAME` IN ('iduser', 'idcategory');
share
...
How do I change the data type for a column in MySQL?
...n type to another type, you can generate queries using a query like this:
select distinct concat('alter table ',
table_name,
' modify ',
column_name,
' <new datatype> ',
if(is_nu...
What's the best way to put a c-struct in an NSArray?
...e don't need a pointer to the values to be stored within. This is distinct from the immutable array wherein the contents are "frozen" at creation and hence values must be passed to the initialisation routine.
– Sedate Alien
Dec 30 '10 at 1:11
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What is the use of Enumerable.Zip extension method in Linq?
...rator merges the corresponding elements of two sequences using a specified selector function.
var letters= new string[] { "A", "B", "C", "D", "E" };
var numbers= new int[] { 1, 2, 3 };
var q = letters.Zip(numbers, (l, n) => l + n.ToString());
foreach (var s in q)
Console.WriteLine(s);
Oupu...
How to create a database from shell command?
... I get this error ERROR 1046 (3D000) at line 27: No database selected when I run echo "create database databasename" | mysql -u -u username -p command
– keerthi
Mar 15 '13 at 5:16
...
How to generate the JPA entity Metamodel?
...EE Developers") has its own metamodel generator integrated with Eclipse.
Select your project in the Package Explorer
Go to Properties -> JPA dialog
Select source folder from Canonical metamodel (JPA 2.0) group
Click Apply button to generate metamodel classes in the selected source folder
Th...
Protecting executable from reverse engineering?
I've been contemplating how to protect my C/C++ code from disassembly and reverse engineering. Normally I would never condone this behavior myself in my code; however the current protocol I've been working on must not ever be inspected or understandable, for the security of various people.
...
Use numpy array in shared memory for multiprocessing
...rray
with shared_arr.get_lock(): # synchronize access
arr = np.frombuffer(shared_arr.get_obj()) # no data copying
arr[i] = -arr[i]
Example
import ctypes
import logging
import multiprocessing as mp
from contextlib import closing
import numpy as np
info = mp.get_logger().info...
What is a “memory stomp”?
...will appear when something tries to access the victim that was stomped on, and the code that stomped on it may be totally unrelated.
Another is accessing memory after it was freed. The memory may be allocated for another object. Again, the code that shows the problem may be related to the newly-all...
Check if at least two out of three booleans are true
...e a&&b || b&&c || a&&c version wins then.
Results from Tofubeer with the latest code running OS X:
a&&b || b&&c || a&&c : 1358 ms
a ? b||c : b&&c : 1187 ms
a&b | b&c | c&a : 410 ms
a + b + c >= 2 : 602 ms
...