大约有 16,000 项符合查询结果（耗时：0.0312秒） [XML]
FIND_IN_SET() vs IN()
... (attachedCompanyIDs)
attachedCompanyIDs is a scalar value which is cast into INT (type of companyID).
The cast only returns numbers up to the first non-digit (a comma in your case).
Thus,
companyID IN ('1,2,3') ≡ companyID IN (CAST('1,2,3' AS INT)) ≡ companyID IN (1)
In PostgreSQL, you c...
How come a non-const reference cannot bind to a temporary object?
...on getx() returns? Clearly, this is prohibited by C++ Standard
but I am interested in the purpose of such restriction, not a reference to the standard.
...
How to hide first section header in UITableView (grouped style)
...- (CGFloat) tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
if (section == 0)
return 1.0f;
return 32.0f;
}
- (NSString*) tableView:(UITableView *) tableView titleForHeaderInSection:(NSInteger)section
{
if (section == 0) {
return nil;
...
“INSERT IGNORE” vs “INSERT … ON DUPLICATE KEY UPDATE”
...:
Inserting a duplicate key in columns with PRIMARY KEY or UNIQUE constraints.
Inserting a NULL into a column with a NOT NULL constraint.
Inserting a row to a partitioned table, but the values you insert don't map to a partition.
If you use REPLACE, MySQL actually does a DELETE followed by an ...
Can I set a breakpoint on 'memory access' in GDB?
I am running an application through gdb and I want to set a breakpoint for any time a specific variable is accessed / changed. Is there a good method for doing this? I would also be interested in other ways to monitor a variable in C/C++ to see if/when it changes.
...
Remove duplicates in the list using linq
...ode == y.Code &&
x.Price == y.Price;
}
public int GetHashCode(Item obj) {
return obj.Id.GetHashCode() ^
obj.Name.GetHashCode() ^
obj.Code.GetHashCode() ^
obj.Price.GetHashCode();
}
}
Then use it like this:
var distinctIt...
Easy way to write contents of a Java InputStream to an OutputStream
...e the input and/or output stream is asynchronously closed, or
the thread interrupted during the transfer, is highly input and output
stream specific, and therefore not specified
So in order to write contents of a Java InputStream to an OutputStream, you can write:
input.transferTo(output);
...
Is this the right way to clean-up Fragment back stack when leaving a deeply nested stack?
...
Well there are a few ways to go about this depending on the intended behavior, but this link should give you all the best solutions and not surprisingly is from Dianne Hackborn
http://groups.google.com/group/android-developers/browse_thread/thread/d2a5c203dad6ec42
Essentially you ha...
Proper stack and heap usage in C++?
... it, you must allocate it on the heap.
class Thingy;
Thingy* foo( )
{
int a; // this int lives on the stack
Thingy B; // this thingy lives on the stack and will be deleted when we return from foo
Thingy *pointerToB = &B; // this points to an address on the stack
Thingy *pointerToC = n...
Why use multiple columns as primary keys (composite primary key)
... the two is guaranteed unique.
The alternative is to use a generated (non-intelligent) primary key, for example in this case OrderDetailId. But then you would not always see the relationship as easily. Some folks prefer one way; some prefer the other way.
...