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Efficient paging in SQLite with millions of records
...ient paging, save the first/last displayed values of the ordered field(s), and continue just after them when displaying the next page:
SELECT *
FROM MyTable
WHERE SomeColumn > LastValue
ORDER BY SomeColumn
LIMIT 100;
(This is explained with more detail on the SQLite wiki.)
When you have multi...
Compare if BigDecimal is greater than zero
...nother proof, if any were needed, that Loki or one of his avatars is alive and well and has moved into software development.)
– Andrew Spencer
Dec 6 '11 at 11:16
11
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Filter rows which contain a certain string
...mail in the comments above. You can use regular expressions for the second and subsequent arguments of filter like this:
dplyr::filter(df, !grepl("RTB",TrackingPixel))
Since you have not provided the original data, I will add a toy example using the mtcars data set. Imagine you are only intereste...
Get the key corresponding to the minimum value within a dictionary
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what if two different keys have the same value? and they happen to both be the smallest value? how can you make it return both?
– user3226932
Dec 18 '16 at 4:29
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Rename an environment with virtualenvwrapper
I have an environment called doors and I would like to rename it to django for the virtualenvwrapper .
2 Answers
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How to make pipes work with Runtime.exec()?
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Write a script, and execute the script instead of separate commands.
Pipe is a part of the shell, so you can also do something like this:
String[] cmd = {
"/bin/sh",
"-c",
"ls /etc | grep release"
};
Process p = Runtime.getRuntime().exec(...
C++: variable 'std::ifstream ifs' has initializer but incomplete type
...is is pretty noobish, but I'm pretty new to C++. I'm trying to open a file and read it using ifstream :
1 Answer
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MySQL Select minimum/maximum among two (or more) given values
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You can use LEAST and GREATEST function to achieve it.
SELECT
GREATEST(A.date0, B.date0) AS date0,
LEAST(A.date1, B.date1) AS date1
FROM A, B
WHERE B.x = A.x
Both are described here http://dev.mysql.com/doc/refman/5.0/en/comparison-...
How to get first record in each group using Linq
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What if want to retrieve the first and last item from the group?
– Sandeep Pandey
Feb 14 at 13:11
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How do I explicitly specify a Model's table-name mapping in Rails?
I have a Model class called Countries and I want it to map to a DB table called 'cc'.
2 Answers
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