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The type 'string' must be a non-nullable type in order to use it as parameter T in the generic type
Why do I get Error "The type 'string' must be a non-nullable value type in order to use it as parameter 'T' in the generic type or method 'System.Nullable'"?
...
Why should I use a pointer rather than the object itself?
...y, you shouldn't abuse it. So here are some disadvantages in no particular order:
It is error-prone. Manual memory allocation is dangerous and you are prone to leaks. If you are not proficient at using the debugger or valgrind (a memory leak tool), you may pull your hair out of your head. Luckily ...
What would cause an algorithm to have O(log n) complexity?
...s assume you have, say, a list of N elements that are sorted in increasing order. You want to find out if some given number exists in that list. One way to do that which is not a binary search is to just scan each element of the list and see if it's your target number. You might get lucky and fin...
Why JSF calls getters multiple times
...public Boolean getGmapsAutoComplete() {
switch (page) {
case "/orders/pf_Add.xhtml":
case "/orders/pf_Edit.xhtml":
case "/orders/pf_EditDriverVehicles.xhtml":
gmapsAutoComplete = true;
break;
default:
gmapsAutoComplete = false;
...
select * vs select column
...as to what you want, it will first need to check the table's definition in order to determine the columns on that table. That lookup will cost some time - not much in a single query - but it adds up over time
if you need only 2/3 of the columns, you're selecting 1/3 too much data which needs to be r...
Meaning of tilde in Linux bash (not home directory)
...tion is usually controlled by NSS; so by default values are pulled out of /etc/passwd, though it can be configured to retrieve the information using any source desired, such as NIS, LDAP or an SQL database.
Tilde expansion is more than home directory lookup. Here's a summary:
~ $HOME
~f...
write a shell script to ssh to a remote machine and execute commands
...ript and put your linux machines IPs, usernames and password in respective order. After that run that script. Thats it ! This script will install VLC in all systems.
#!/bin/bash
SCRIPT="cd Desktop; pwd; echo -e 'PASSWORD' | sudo -S apt-get install vlc"
HOSTS=("192.168.1.121" "192.168.1.122" "192.1...
View's SELECT contains a subquery in the FROM clause
...y client_id
create view view_credit_status as
select
credit_orders.client_id,
sum(credit_orders.number_of_credits) as purchased,
ifnull(t1.credits_used,0) as used
from credit_orders
left outer join view_clients_credit_usage as t1 on t1.client_id = credit_ord...
How to get all possible combinations of a list’s elements?
...
the input iterable.
Combinations are emitted in lexicographic sort order. So, if the
input iterable is sorted, the
combination tuples will be produced in
sorted order.
Since 2.6, batteries are included!
share...
ASP.Net MVC: How to display a byte array image from model
...
Great, I added a method on my model in order to re use it :public string GetBase64() { var base64 = Convert.ToBase64String(ContentImage); return String.Format("data:image/gif;base64,{0}", base64); }
– R...