大约有 42,000 项符合查询结果（耗时：0.0716秒） [XML]
How can a LEFT OUTER JOIN return more records than exist in the left table?
I have a very basic LEFT OUTER JOIN to return all results from the left table and some additional information from a much bigger table. The left table contains 4935 records yet when I LEFT OUTER JOIN it to an additional table the record count is significantly larger.
...
What exactly is OAuth (Open Authorization)?
What exactly is OAuth (Open Authorization)?
9 Answers
9
...
Can table columns with a Foreign Key be NULL?
I have a table which has several ID columns to other tables.
7 Answers
7
...
How does the “final” keyword in Java work? (I can still modify an object.)
In Java we use final keyword with variables to specify its values are not to be changed.
But I see that you can change the value in the constructor / methods of the class. Again, if the variable is static then it is a compilation error.
...
In c# what does 'where T : class' mean?
In C# what does where T : class mean?
10 Answers
10
...
Better explanation of when to use Imports/Depends
The " Writing R Extensions " manual provides the following guidance on when to use Imports or Depends:
4 Answers
...
What is base 64 encoding used for?
I've heard people talking about "base 64 encoding" here and there. What is it used for?
18 Answers
...
Android Min SDK Version vs. Target SDK Version
When it comes to developing applications for Android, what is the difference between Min and Target SDK version? Eclipse won't let me create a new project unless Min and Target versions are the same!
...
How do you merge two Git repositories?
Consider the following scenario:
23 Answers
23
...
How do you turn a Mongoose document into a plain object?
I have a document from a mongoose find that I want to extend before JSON encoding and sending out as a response. If I try adding properties to the doc it is ignored. The properties don't appear in Object.getOwnPropertyNames(doc) making a normal extend not possible. The strange thing is that JSON....