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What is the difference between ExecuteScalar, ExecuteReader and ExecuteNonQuery?
What are the different cases when we use these three? Where should I use one and where should I not?
9 Answers
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The JPA hashCode() / equals() dilemma
There have been some discussions here about JPA entities and which hashCode() / equals() implementation should be used for JPA entity classes. Most (if not all) of them depend on Hibernate, but I'd like to discuss them JPA-implementation-neutrally (I am using EclipseLink, by the way).
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How do I create an Excel (.XLS and .XLSX) file in C# without installing Microsoft Office?
How can I create an Excel spreadsheet with C# without requiring Excel to be installed on the machine that's running the code?
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INNER JOIN ON vs WHERE clause
For simplicity, assume all relevant fields are NOT NULL .
11 Answers
11
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How to count TRUE values in a logical vector
In R, what is the most efficient/idiomatic way to count the number of TRUE values in a logical vector? I can think of two ways:
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Custom domain for GitHub project pages
I have a gh-pages branch in one of my http://github.com repos. The GitHub project pages works fine if I go to http://myuser.github.com/myrepo
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What is the “N+1 selects problem” in ORM (Object-Relational Mapping)?
The "N+1 selects problem" is generally stated as a problem in Object-Relational mapping (ORM) discussions, and I understand that it has something to do with having to make a lot of database queries for something that seems simple in the object world.
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Cannot delete directory with Directory.Delete(path, true)
I'm using .NET 3.5, trying to recursively delete a directory using:
30 Answers
30
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How to differ sessions in browser-tabs?
In a web-application implemented in java using JSP and Servlets; if I store information in the user session, this information is shared from all the tabs from the same browser. How to differ sessions in the browser-tabs?
In this example:
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What should I do if two libraries provide a function with the same name generating a conflict?
What should I do if I have two libraries that provide functions with equivalent names?
12 Answers
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