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What is the difference between gmake and make?
... make implementations of various commercial unixes.
The language accepted by GNU make is a superset of the one supported by the traditional make utility.
By using 'gmake' specifically you can use GNU make extensions without worrying about them being misinterpreted by some other make implementation...
How do I modify a MySQL column to allow NULL?
...
ALTER TABLE mytable MODIFY mycolumn VARCHAR(255);
Columns are nullable by default. As long as the column is not declared UNIQUE or NOT NULL, there shouldn't be any problems.
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LISTAGG in Oracle to return distinct values
...c and later:
select listagg(distinct the_column, ',') within group (order by the_column)
from the_table
18c and earlier:
select listagg(the_column, ',') within group (order by the_column)
from (
select distinct the_column
from the_table
) t
If you need more columns, something like this ...
Entity Framework Code First - two Foreign Keys from same table
... .WillCascadeOnDelete(false);
}
}
Primary keys are mapped by default convention. Team must have two collection of matches. You can't have single collection referenced by two FKs. Match is mapped without cascading delete because it doesn't work in these self referencing many-to-many....
Multiple commands on a single line in a Windows batch file
... tend to be evaluated on read rather than execute.
You can get round this by turning on delayed expansion:
pax> cmd /v:on /c "echo !time! & ping 127.0.0.1 >nul: & echo !time!"
15:23:36.77
15:23:39.85
That's needed from the command line. If you're doing this inside a script, you can...
Git: Pull from other remote
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Can TCP and UDP sockets use the same port?
...level (OSI model level 4). So TCP has its own ports, which are interpreted by the TCP stack; UDP has its own ports, which are interpreted by the UDP stack. So to say, ports are not shared between UDP and TCP; it just happens that both protocols have the same definition of "ports" and that in order t...
dplyr: “Error in n(): function should not be called directly”
...
As mentioned by the previous answer, you may have a conflict between plyr and dplyr. You can to run this command to unload the plyr package.
detach("package:plyr", unload=TRUE)
Then you can continue as expected.
library(dplyr)
...
...
What are paramorphisms?
...dr c n [] = n
Some people call paramorphisms "primitive recursion" by contrast with catamorphisms (foldr) being "iteration".
Where foldr's two parameters are given a recursively computed value for each recursive subobject of the input data (here, that's the tail of the list), para's paramet...
Merge cells using EPPlus?
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