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Why is super.super.method(); not allowed in Java?
...hat you can access shadowed variables from superclasses of superclasses by casting this:
interface I { int x = 0; }
class T1 implements I { int x = 1; }
class T2 extends T1 { int x = 2; }
class T3 extends T2 {
int x = 3;
void test() {
System.out.println("x=\t\t" ...
Postgresql SELECT if string contains
...eld of the record. Concatenate using '||' with the literal percent signs:
SELECT id FROM TAG_TABLE WHERE 'aaaaaaaa' LIKE '%' || tag_name || '%';
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Rank function in MySQL
...
One option is to use a ranking variable, such as the following:
SELECT first_name,
age,
gender,
@curRank := @curRank + 1 AS rank
FROM person p, (SELECT @curRank := 0) r
ORDER BY age;
The (SELECT @curRank := 0) part allows the variable initializatio...
Check if a Postgres JSON array contains a string
...
As of PostgreSQL 9.4, you can use the ? operator:
select info->>'name' from rabbits where (info->'food')::jsonb ? 'carrots';
You can even index the ? query on the "food" key if you switch to the jsonb type instead:
alter table rabbits alter info type jsonb using ...
What exactly do “IB” and “UB” mean?
...by the compiler writers. An example of this is the result of a reinterpret_cast. usually, it simply changes the type of a pointer, without modifying the address, but the mapping is actually implementation-defined, so a compiler could map to a completely different address, as long as it documented th...
How to Programmatically Add Views to Views
...
As a coding practice, on findViewById, cast to ViewGroup or always the most generic form of an object so that if it changes from a LinearLayout to a RelativeLayout, you have no refactoring.
– Joel Teply
Apr 3 '15 at 16:59
...
How to convert a Base64 string into a Bitmap image to show it in a ImageView?
... to you from API is Base64 Encoded and should be decoded first in order to cast it to a Bitmap object!
-Take a look at your Base64 encoded String, If it starts with
data:image/jpg;base64
The Base64.decode won't be able to decode it, So it has to be removed from your encoded String:
final Str...
How to avoid using Select in Excel VBA
I've heard much about the understandable abhorrence of using .Select in Excel VBA, but am unsure of how to avoid using it. I am finding that my code would be more re-usable if I were able to use variables instead of Select functions. However, I am not sure how to refer to things (like the Activ...
Why doesn't java.util.Set have get(int index)?
...tem, I can
use set.iterator().next(), but
otherwise it seems I have to cast to
an Array to retrieve an item at a
specific index?
What are the appropriate ways of
retrieving data from a set? (other
than using an iterator)
You should also familiarise yourself with the SortedSet inte...
SQL SELECT speed int vs varchar
...k: A=261MB B=292MB C=322MB
Non-indexed by id: select count(*), select by id: 450ms same on all tables
Insert* one row per TX: B=9ms/record C=9ms/record
Bulk insert* in single TX: B=140usec/record C=180usec/record
Indexed by id, select by id: B=about 2...