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Counting null and non-null values in a single query
... to get it to work on another RDBMS):
select sum(case when a is null then 1 else 0 end) count_nulls
, count(a) count_not_nulls
from us;
Or:
select count(*) - count(a), count(a) from us;
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Mac OSX Lion DNS lookup order [closed]
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10 Answers
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Autowiring two beans implementing same interface - how to set default bean to autowire?
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134
I'd suggest marking the Hibernate DAO class with @Primary, i.e. (assuming you used @Repository...
Need for predictable random generator
... a player has 20% chance to get a critical hit with his sword. That means, 1 out of 5 hits should be critical. The problem is I got very bad real life results — sometimes players get 3 crits in 5 hits, sometimes none in 15 hits. Battles are rather short (3-10 hits) so it's important to get good ra...
LINQ with groupby and count
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412
After calling GroupBy, you get a series of groups IEnumerable<Grouping>, where each Group...
How to define a function in ghci across multiple lines?
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125
For guards (like your example), you can just put them all on one line and it works (guards do ...
'float' vs. 'double' precision
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146
Floating point numbers in C use IEEE 754 encoding.
This type of encoding uses a sign, a signi...
How to use Swift @autoclosure
...}
}
To call this function, we have to pass in a closure
f(pred: {2 > 1})
// "It's true"
If we omit the braces, we are passing in an expression and that's an error:
f(pred: 2 > 1)
// error: '>' produces 'Bool', not the expected contextual result type '() -> Bool'
@autoclosure crea...