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Schrödingers MySQL table: exists, yet it does not
I am having the weirdest error of all.
11 Answers
11
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Missing Maven dependencies in Eclipse project
We have a project set up with maven for resolving dependancies. It usually works fine, but now I am trying to compile and run it on a new PC and I have problem with missing dependencies in Eclipse.
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Best way to combine two or more byte arrays in C#
...able<byte> using LINQ's Concat<> - 0.0781265 seconds
Finally, I increased the size of each array to 1 million elements and re-ran the test, executing each loop only 4000 times:
New Byte Array using System.Array.Copy - 13.4533833 seconds
New Byte Array using System.Buffer....
Difference between wait and sleep
... process ID or a job specification; if a
job spec is given, all processes in that job's pipeline are
waited for. If n is not given, all currently active child pro-
cesses are waited for, and the return status is zero. If n
specifies a non-existent proc...
Java's Interface and Haskell's type class: differences and similarities?
...d say that an interface is kind of like a type class SomeInterface t where all of the values have the type t -> whatever (where whatever does not contain t). This is because with the kind of inheritance relationship in Java and similar languages, the method called depends on the type of object th...
System.currentTimeMillis() vs. new Date() vs. Calendar.getInstance().getTime()
...ost efficient since it does not even create an object, but new Date() is really just a thin wrapper about a long, so it is not far behind. Calendar, on the other hand, is relatively slow and very complex, since it has to deal with the considerably complexity and all the oddities that are inherent to...
MySQL: multiple tables or one table with many columns?
...elational database to minimize redundancy and dependency. Normalization usually involves dividing large tables into smaller (and less redundant) tables and defining relationships between them. The objective is to isolate data so that additions, deletions, and modifications of a field can be made in ...
How do you pass multiple enum values in C#?
... if (isTuesdaySet)
//...
// Do your work here..
}
public void CallMethodWithTuesdayAndThursday()
{
this.RunOnDays(DaysOfWeek.Tuesday | DaysOfWeek.Thursday);
}
For more details, see MSDN's documentation on Enumeration Types.
Edit in response to additions to question.
You won't b...
Create a date from day month and year with T-SQL
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Assuming y, m, d are all int, how about:
CAST(CAST(y AS varchar) + '-' + CAST(m AS varchar) + '-' + CAST(d AS varchar) AS DATETIME)
Please see my other answer for SQL Server 2012 and above
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SQL JOIN - WHERE clause vs. ON clause
...der and its lines, if any, for order number 12345. The second will return all orders, but only order 12345 will have any lines associated with it.
With an INNER JOIN, the clauses are effectively equivalent. However, just because they are functionally the same, in that they produce the same results...