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insert a NOT NULL column to an existing table
...with valid not null values and finally ALTER column to set NOT NULL constraint:
ALTER TABLE MY_TABLE ADD STAGE INT NULL
GO
UPDATE MY_TABLE SET <a valid not null values for your column>
GO
ALTER TABLE MY_TABLE ALTER COLUMN STAGE INT NOT NULL
GO
Another option is to specify correct default va...
Random number generator only generating one random number
...);
private static readonly object syncLock = new object();
public static int RandomNumber(int min, int max)
{
lock(syncLock) { // synchronize
return random.Next(min, max);
}
}
Edit (see comments): why do we need a lock here?
Basically, Next is going to change the internal stat...
Using Case/Switch and GetType to determine the object [duplicate]
... .ToString(). However, I would avoid it at all costs: IDictionary<Type, int> will do much better, visitor might be an overkill but otherwise it is still a perfectly fine solution.
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impr...
Why does JPA have a @Transient annotation?
...he transient keyword, that field will not be serialized when the object is converted to a byte stream. Furthermore, since JPA treats fields marked with the transient keyword as having the @Transient annotation, the field will not be persisted by JPA either.
On the other hand, fields annotated @Tra...
How to use the toString method in Java?
... returns a string equal to the value
of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
Example:
String[] mystr ={"a","b","c"};
System.out.println("mystr.toString: " + mystr.toString());
output:- mystr.toString: [Ljava.lang.String;@13aaa14a
...
std::auto_ptr to std::unique_ptr
...a unique_ptr can only be moved. Anything that looks like
std::auto_ptr<int> p(new int);
std::auto_ptr<int> p2 = p;
will have to become at least like this
std::unique_ptr<int> p(new int);
std::unique_ptr<int> p2 = std::move(p);
As for other differences, unique_ptr can h...
How can I remove duplicate rows?
...you have a GUID instead of an integer, you can replace
MIN(RowId)
with
CONVERT(uniqueidentifier, MIN(CONVERT(char(36), MyGuidColumn)))
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foll...
Difference between final and effectively final
...statement in the PhoneNumber constructor:
public class OutterClass {
int numberLength; // <== not *final*
class PhoneNumber {
PhoneNumber(String phoneNumber) {
numberLength = 7; // <== assignment to numberLength
String currentNumber = phoneNumber.replaceAll(
...
Error: Jump to case label
...ich does exist but probably contains garbage.
switch(foo) {
case 1:
int i = 42; // i exists all the way to the end of the switch
dostuff(i);
break;
case 2:
dostuff(i*2); // i is *also* in scope here, but is not initialized!
}
Wrapping the case in an explicit block solves the p...
C++ Erase vector element by value rather than by position? [duplicate]
... to get an iterator to a value:
#include <algorithm>
std::vector<int>::iterator position = std::find(myVector.begin(), myVector.end(), 8);
if (position != myVector.end()) // == myVector.end() means the element was not found
myVector.erase(position);
...