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How do I find duplicates across multiple columns?
...s
join (
select name, city, count(*) as qty
from [stuff]
group by name, city
having count(*) > 1
) t on s.name = t.name and s.city = t.city
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How does the Brainfuck Hello World actually work?
... understand Brainfuck you must imagine infinite array of cells initialized by 0 each.
...[0][0][0][0][0]...
When brainfuck program starts, it points to any cell.
...[0][0][*0*][0][0]...
If you move pointer right > you are moving pointer from cell X to cell X+1
...[0][0][0][*0*][0]...
If ...
How does the Java 'for each' loop work?
...r ( : ) idiom, since the actual iterator is merely inferred.
As was noted by Denis Bueno, this code works for any object that implements the Iterable interface.
Also, if the right-hand side of the for (:) idiom is an array rather than an Iterable object, the internal code uses an int index counter...
Select SQL Server database size
...er_files WITH(NOWAIT)
WHERE database_id = DB_ID() -- for current db
GROUP BY database_id
Output:
-- my query
name log_size_mb row_size_mb total_size_mb
-------------- ------------ ------------- -------------
xxxxxxxxxxx 512.00 302.81 814.81
-- sp_spaceused
database_...
What does “Memory allocated at compile time” really mean?
... array at compile-time. Also a global variable has static storage duration by default: it is allocated in the static memory area of the process memory space (.data/.bss section). Given that information, the compiler decides during compilation in what address of that static memory area the array wil...
What exactly are unmanaged resources?
...
Managed resources basically means "managed memory" that is managed by the garbage collector. When you no longer have any references to a managed object (which uses managed memory), the garbage collector will (eventually) release that memory for you.
Unmanaged resources are then everything t...
Count the occurrences of DISTINCT values
..., count the number of occurrences of that value and then order the results by the count.
3 Answers
...
How do CDI and EJB compare? interact?
...d EJB there at all).
EJB: you do understand, and probably you are confused by @EJB annotation - it allows you to inject implementation into your service or whatever. The main idea is that class, where you inject, should be managed by EJB container.
Seems that CDI does understand what EJB is, so in J...
How to know user has clicked “X” or the “Close” button?
...on't need, according to me, to differentiate from either buttons.
Closing by ALT+F4 will also trigger the FormClosing() event, as it sends a message to the Form that says to close. You may cancel the event by setting the
FormClosingEventArgs.Cancel = true.
In our example, this would translate ...
What's the fastest way to merge/join data.frames in R?
... dt <- data.table(d, key = "g1,g2")
dt[, colMeans(cbind(x, y)), by = "g1,g2"]
},
plyr = ddply(d, .(g1, g2), summarise, avx = mean(x), avy=mean(y)),
sqldf = sqldf(c("create index ix on d(g1, g2)",
"select g1, g2, avg(x), avg(y) from main.d group by g1, g2"))
)
The outputs ...