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Does Foreign Key improve query performance?
Suppose I have 2 tables, Products and ProductCategories. Both tables have relationship on CategoryId. And this is the query.
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How to zero pad a sequence of integers in bash so that all have the same width?
...speaking, seq supports a subset of the format chars. that printf supports (and that subsets includes g, but not d). The behavior of characters d and g differs subtly in that d interprets 0-prefixed numbers strings as octal numbers and converts them to decimal, whereas g treats them as decimals. (@Ed...
Entity Framework vs LINQ to SQL
...LINQ to SQL only supports 1 to 1 mapping of database tables, views, sprocs and functions available in Microsoft SQL Server. It's a great API to use for quick data access construction to relatively well designed SQL Server databases. LINQ2SQL was first released with C# 3.0 and .Net Framework 3.5.
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XMLHttpRequest cannot load file. Cross origin requests are only supported for HTTP
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If you are doing something like writing HTML and Javascript in a code editor on your personal computer, and testing the output in your browser, you will probably get error messages about Cross Origin Requests. Your browser will render HTML and run Javascript, jQuery, a...
Hibernate: hbm2ddl.auto=update in production?
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Also updating a db schema should be handled by the professionals ( dbas ). Recovering from a bad db change is difficult at best. Vova didn't mention it - but what happens if hibernate's update decides to drop a column and re-add it because the type or size chan...
How to get all options of a select using jQuery?
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$.map is much more elegant and less error prone (see below).
– Elliot Cameron
Nov 15 '16 at 19:13
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Cannot read configuration file due to insufficient permissions
...s (Network Services, Local System, etc.), should have permission to access and read web.config file.
Update:
This updated answer is same as above, but a little longer and simpler and improved.
First of all: you don't have to change anything in your config file. It's OK. The problem is with window...
How to implement Android Pull-to-Refresh
In Android applications such as Twitter (official app), when you encounter a ListView, you can pull it down (and it will bounce back when released) to refresh the content.
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How to delete items from a dictionary while iterating over it?
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EDIT:
This answer will not work for Python3 and will give a RuntimeError.
RuntimeError: dictionary changed size during iteration.
This happens because mydict.keys() returns an iterator not a list.
As pointed out in comments simply convert mydict.keys() to a list ...
What is Func, how and when is it used
What is Func<> and what is it used for?
7 Answers
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