大约有 15,000 项符合查询结果（耗时：0.0394秒） [XML]
NULL values inside NOT IN clause
This issue came up when I got different records counts for what I thought were identical queries one using a not in where constraint and the other a left join . The table in the not in constraint had one null value (bad data) which caused that query to return a count of 0 records. I sort of u...
What is uintptr_t data type
What is uintptr_t and what can it be used for?
5 Answers
5
...
Is std::unique_ptr required to know the full definition of T?
I have some code in a header that looks like this:
8 Answers
8
...
Node.js version on the command line? (not the REPL)
I want to get the version of Node.js on the command line. I'm expecting to run a command like:
14 Answers
...
How to do a FULL OUTER JOIN in MySQL?
I want to do a Full Outer Join in MySQL. Is this possible? Is a Full Outer Join supported by MySQL?
15 Answers
...
What's the difference between equal?, eql?, ===, and ==?
I am trying to understand the difference between these four methods. I know by default that == calls the method equal? which returns true when both operands refer to exactly the same object.
...
How to use glOrtho() in OpenGL?
I can't understand the usage of glOrtho . Can someone explain what it is used for?
3 Answers
...
Git - How to close commit editor?
I'm new to git and learning from a PDF.
I just executed a command $ git commit and it opens a new editor. But I'm trying to close that new commit editor. How to do this? I'm using git on windows.
...
How do I calculate the normal vector of a line segment?
Suppose I have a line segment going from (x1,y1) to (x2,y2). How do I calculate the normal vector perpendicular to the line?
...
Regex for quoted string with escaping quotes
How do I get the substring " It's big \"problem " using a regular expression?
16 Answers
...