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Test if string is a guid without throwing exceptions?
... class identifier</param>
/// <returns>
/// Positive or zero if class identifier was obtained successfully
/// Negative if the call failed
/// </returns>
[DllImport("ole32.dll", CharSet = CharSet.Unicode, ExactSpelling = true, PreserveSig = t...
What is the most efficient/elegant way to parse a flat table into a tree?
... all popular SQL databases support recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentId = t.Id
)
SELECT * FROM MyTree;
I tested recursive queries in MySQL 8.0...
Why does Java have transient fields?
...ike to a file) process.
From the Java Language Specification, Java SE 7 Edition, Section 8.3.1.3. transient Fields:
Variables may be marked transient to
indicate that they are not part of the
persistent state of an object.
For example, you may have fields that are derived from other field...
Most efficient method to groupby on an array of objects
...follow
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edited Mar 26 at 21:11
answered Jan 20 '16 at 2:02
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C default arguments
...
Not really. The only way would be to write a varargs function and manually fill in default values for arguments which the caller doesn't pass.
share
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improve thi...
Like Operator in Entity Framework?
We're trying to implement the "LIKE" operator in Entity Framework for our entities with string fields, but it doesn't appear to be supported. Has anyone else tried to do something like this?
...
How to select all records from one table that do not exist in another table?
... all rows from table1 and for each row we attempt to find a row in table2 with the same value for the name column. If there is no such row, we just leave the table2 portion of our result empty for that row. Then we constrain our selection by picking only those rows in the result where the matching r...
How do I use a custom deleter with a std::unique_ptr member?
I have a class with a unique_ptr member.
6 Answers
6
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Can I extend a class using more than 1 class in PHP?
If I have several classes with functions that I need but want to store separately for organisation, can I extend a class to have both?
...
Python append() vs. + operator on lists, why do these give different results?
...l array, which results in a reference to self in that spot (hence the infinite recursion).
The difference here is that the + operation acts specific when you add an array (it's overloaded like others, see this chapter on sequences) by concatenating the element. The append-method however does literal...