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SQL - using alias in Group By
... following order:
FROM clause
WHERE clause
GROUP BY clause
HAVING clause
SELECT clause
ORDER BY clause
For most relational database systems, this order explains which names (columns or aliases) are valid because they must have been introduced in a previous step.
So in Oracle and SQL Server, you...
Python nonlocal statement
...eavily indented when defining inner functions and ends up violating the 79 chars PEP8 recommendation. Any way to get around this problem? Can an inner function somehow be placed outside the outer function? I know the question sounds stupid, but I'm earnest.
– tommy.carstensen
...
What does the “__block” keyword mean?
...c NSInteger CounterStatic;
{
NSInteger localCounter = 42;
__block char localCharacter;
void (^aBlock)(void) = ^(void) {
++CounterGlobal;
++CounterStatic;
CounterGlobal = localCounter; // localCounter fixed at block creation
localCharacter = 'a'; // sets ...
in_array multiple values
... developer, you should probably start learning set operations (difference, union, intersection). You can imagine your array as one "set", and the keys you are searching for the other.
Check if ALL needles exist
function in_array_all($needles, $haystack) {
return empty(array_diff($needles, $hays...
sqlalchemy: how to join several tables by one query?
...sn't do a join at all" - that's a little misleading. It will have sql like select x from a, b ,c which is a cross join. The filters then make it an inner join.
– Aidan Kane
Sep 12 '16 at 13:04
...
When should you use a class vs a struct in C++?
... class that has no non-static data members of type non-POD-struct, non-POD-union (or array of such types) or reference, and has no user-defined copy assignment operator and no user-defined destructor." There is no restriction on using the "struct" class-key and no restriction on using "public" (see...
Generating random numbers in Objective-C
...
arc4random_stir(void);
void
arc4random_addrandom(unsigned char *dat, int datlen);
DESCRIPTION
The arc4random() function uses the key stream generator employed by the arc4 cipher, which uses 8*8 8
bit S-Boxes. The S-Boxes can be in about (2**1700) states. The arc4random(...
SQL Server - copy stored procedures from one db to another
...
Right click on database
Tasks
Generate Scripts
Select the objects you wish to script
Script to File
Run generated scripts against target database
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Oracle SQL: Update a table with data from another table
...his is called a correlated update
UPDATE table1 t1
SET (name, desc) = (SELECT t2.name, t2.desc
FROM table2 t2
WHERE t1.id = t2.id)
WHERE EXISTS (
SELECT 1
FROM table2 t2
WHERE t1.id = t2.id )
Assuming the join results in a key-pr...
Setting custom UITableViewCells height
...Size:14.0f] constrainedToSize:constraintSize lineBreakMode:UILineBreakModeCharacterWrap]
if ( neededSize.height <= 18)
return 45
else return neededSize.height + 45
//18 is the size of your text with the requested font (systemFontOfSize 14). if you change fonts you have a different number t...