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Extracting specific columns from a data frame
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It convert data frame to list.
– Suat Atan PhD
Jun 21 '17 at 9:42
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How to select multiple rows filled with constants?
...LUES
(1, 2),
(3, 4)
) AS q (col1, col2)
In other systems, just use UNION ALL:
SELECT 1 AS col1, 2 AS col2
-- FROM dual
-- uncomment the line above if in Oracle
UNION ALL
SELECT 3 AS col1, 3 AS col2
-- FROM dual
-- uncomment the line above if in Oracle
In Oracle, ...
Does use of final keyword in Java improve the performance?
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}
if (doSomething) {
// do finalization part.
}
}
By converting the doSomething attribute into a final attribute, you have told the compiler that whenever it sees doSomething, it should replace it with false as per the compile-time substitution rules. The first pass of the comp...
How do you calculate the average of a set of circular data? [closed]
... Your maths library probably uses Radians for angles. Remember to convert.
– Martin Beckett
Nov 27 '09 at 23:51
2
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Why do we need argc while there is always a null at the end of argv?
...cts), you can just omit the parameter name, like this C++ snippet (easy to convert to C):
#include <stdio.h> // C-compatible include, guarantees puts in global namespace
// program will print contents of argv, one item per line, starting from argv[0]
int main(int /*argc*/, char *argv[]) { /...
List of Stored Procedures/Functions Mysql Command Line
...lved this answer into select db,name,type from mysql.proc where db<>'sys'; for a bit more info, and less built-in system kruft.
– pbnelson
Aug 16 '19 at 14:49
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How to avoid scientific notation for large numbers in JavaScript?
JavaScript converts a large INT to scientific notation when the number becomes large. How can I prevent this from happening?
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Python : List of dict, if exists increment a dict value, if not append a new dict
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The second version is good since I can convert the dict as a list after.
– Natim
Nov 7 '09 at 8:32
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Adding an identity to an existing column
...t can also be used in non-partitioned tables too.
I've used this trick to convert, in under 5 seconds, a column of a of a 2.5 billion row table from IDENTITY to a non-IDENTITY (in order to run a multi-hour query whose query plan worked better for non-IDENTITY columns), and then restored the IDENTIT...
Parameterize an SQL IN clause
...["@tagNames"].TypeName = "dbo.TagNamesTableType";
// Extension method for converting IEnumerable<string> to IEnumerable<SqlDataRecord>
public static IEnumerable<SqlDataRecord> AsSqlDataRecord(this IEnumerable<string> values, string columnName) {
if (values == null || !va...