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How can I use interface as a C# generic type constraint?
...var check in par[i].GetCustomAttributes(typeof(ConstraintAttribute), true).Cast<ConstraintAttribute>())
{
if (!check.Check(args[i]))
{
string error = "Runtime type check failed for type " + t.ToStri...
COUNT DISTINCT with CONDITIONS
...
You can try this:
select
count(distinct tag) as tag_count,
count(distinct (case when entryId > 0 then tag end)) as positive_tag_count
from
your_table_name;
The first count(distinct...) is easy.
The second one, looks somewhat complex...
MySQL and GROUP_CONCAT() maximum length
...You should use it like this.
SET SESSION group_concat_max_len = 1000000;
select group_concat(column) from table group by column
You can do this even in sharing hosting, but when you use an other session, you need to repeat the SET SESSION command.
...
MySQL Data - Best way to implement paging?
...e LIMIT clause can be used to constrain the number of rows returned by the SELECT statement. LIMIT takes one or two numeric arguments, which must both be nonnegative integer constants (except when using prepared statements).
With two arguments, the first argument specifies the offset of the first ro...
How do you count the lines of code in a Visual Studio solution?
...solution's directory:
PS C:\Path> (gci -include *.cs,*.xaml -recurse | select-string .).Count
8396
PS C:\Path>
That will count the non-blank lines in all the solution's .cs and .xaml files. For a larger project, I just used a different extension list:
PS C:\Other> (gci -include *.cs,*....
Xcode duplicate/delete line
...ct with the following content and restart Xcode.
{
"^$K" = (
"selectLine:",
"cut:"
);
"^$D" = (
"selectLine:",
"copy:",
"moveToEndOfLine:",
"insertNewline:",
"paste:",
"deleteBackward:"
);
}
This will create two shor...
GridCtrl 控件FAQ - C/C++ - 清泛网 - 专注C/C++及内核技术
...能被选中（默认就是固定的不能被选）
m_Grid.SetFixedColumnSelection(FALSE);
m_Grid.SetFixedRowSelection(FALSE);
//设置控件是否允许隐藏行或者列
m_Grid.EnableColumnHide(FALSE);
m_Grid.EnableRowHide(FALSE);
//设置控件是否允许编辑
m_Grid.SetEditable(FA...
LINQ to SQL Left Outer Join
...table), where-as yours matches only 0-1. To do a left outer join, you need SelectMany and DefaultIfEmpty, for example:
var query = from c in db.Customers
join o in db.Orders
on c.CustomerID equals o.CustomerID into sr
from x in sr.DefaultIfEmpty()
s...
Can PHP PDO Statements accept the table or column name as parameter?
... case 1:
$tbl = 'users';
break;
}
$sql = "SELECT * FROM $tbl";
}
By leaving no default case or using a default case that returns an error message you ensure that only values that you want used get used.
...
Can I have multiple Xcode versions installed?
... explicitly specify it at install time. Also, you will generally want to unselect all features besides the xcode core tools, because the others don't let you change the install directory.
– Paul Du Bois
Jul 3 '11 at 3:30
...