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What arguments are passed into AsyncTask?
...here all the stuff you want to do in the background, in a different thread from the main one. Here we have as an input value an array of objects from the type “X” (Do you see in the header? We have “...extends AsyncTask” These are the TYPES of the input parameters) and returns an object from...
Define variable to use with IN operator (T-SQL)
... VALUES (2)
INSERT INTO @MyList VALUES (3)
INSERT INTO @MyList VALUES (4)
SELECT *
FROM MyTable
WHERE MyColumn IN (SELECT Value FROM @MyList)
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Row Offset in SQL Server
...
I would avoid using SELECT *. Specify columns you actually want even though it may be all of them.
SQL Server 2005+
SELECT col1, col2
FROM (
SELECT col1, col2, ROW_NUMBER() OVER (ORDER BY ID) AS RowNum
FROM MyTable
) AS MyDerivedTable...
Why does this method print 4?
...P, then 0 will be printed. If P requires more space, then we remove frames from the stack, gaining R memory at the cost of cnt++.
When println is finally able to run, X - M - (C - cnt) * R >= P. So if P is large for a particular system, then cnt will be large.
Let's look at this with some exa...
Real life example, when to use OUTER / CROSS APPLY in SQL
...1) Top N per group queries (can be more efficient for some cardinalities)
SELECT pr.name,
pa.name
FROM sys.procedures pr
OUTER APPLY (SELECT TOP 2 *
FROM sys.parameters pa
WHERE pa.object_id = pr.object_id
ORDER BY pr.n...
Concurrent.futures vs Multiprocessing in Python 3
...you referenced, but I'm adding an import statement needed to make it work:
from concurrent.futures import ProcessPoolExecutor
def pool_factorizer_map(nums, nprocs):
# Let the executor divide the work among processes by using 'map'.
with ProcessPoolExecutor(max_workers=nprocs) as executor:
...
Convert Rows to columns using 'Pivot' in SQL Server
...9, 3, 87);
If your values are known, then you will hard-code the query:
select *
from
(
select store, week, xCount
from yt
) src
pivot
(
sum(xcount)
for week in ([1], [2], [3])
) piv;
See SQL Demo
Then if you need to generate the week number dynamically, your code will be:
DECLARE @c...
quick random row selection in Postgres
...
You might want to experiment with OFFSET, as in
SELECT myid FROM mytable OFFSET floor(random()*N) LIMIT 1;
The N is the number of rows in mytable. You may need to first do a SELECT COUNT(*) to figure out the value of N.
Update (by Antony Hatchkins)
You must use floor he...
How to use count and group by at the same select statement
I have an sql select query that has a group by.
I want to count all the records after the group by statement.
Is there a way for this directly from sql?
For example, having a table with users I want to select the different towns and the total number of users
...
SET versus SELECT when assigning variables?
What are the differences between the SET and SELECT statements when assigning variables in T-SQL?
4 Answers
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