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postgresql return 0 if returned value is null
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182
use coalesce
COALESCE(value [, ...])
The COALESCE function returns the first of its argume...
must appear in the GROUP BY clause or be used in an aggregate function
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Yes, this is a common aggregation problem. Before SQL3 (1999), the selected fields must appear in the GROUP BY clause[*].
To workaround this issue, you must calculate the aggregate in a sub-query and then join it with itself to get the additional columns you'd need to show:
SEL...
sql ORDER BY multiple values in specific order?
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183
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WHERE
x_field IN ('f', 'p', 'i', 'a') ...
ORDER BY
CASE x_field
WHEN 'f' THEN ...
How do CUDA blocks/warps/threads map onto CUDA cores?
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124
Two of the best references are
NVIDIA Fermi Compute Architecture Whitepaper
GF104 Reviews
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What is the exact difference between currentTarget property and target property in javascript
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451
Basically, events bubble by default so the difference between the two is:
target is the elemen...
Difference between DateTime and Time in Ruby
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179
Newer versions of Ruby (2.0+) do not really have significant differences between the two class...
How to find files that match a wildcard string in Java?
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16 Answers
16
Active
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What is & used for
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130
& is HTML for "Start of a character reference".
& is the character reference for ...
How to create a sub array from another array in Java?
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313
You can use
JDK > 1.5
Arrays.copyOfRange(Object[] src, int from, int to)
Javadoc
J...