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Create code first, many to many, with additional fields in association table
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It's not possible to create a many-to-many relationship with a customized join table. In a many-to-many relationship EF manages the join table internally and hidden. It's a table without an Entity class in your model. To work with such a j...
What is the difference between null and undefined in JavaScript?
I want to know what the difference is between null and undefined in JavaScript.
33 Answers
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浅谈Heatmap：网页热点图生成原理 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...志，当然你也可以使用Perl或别的你熟悉的语言：
#!/usr/bin/awk -f
BEGIN {
FS="&";
}
NF == 4 {
param["page_x"] = "0";
param["page_y"] = "0";
param["screen_width"] = "0";
param["screen_height"] = "0";
split($0, query, "&");
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Generate random integers between 0 and 9
How can I generate random integers between 0 and 9 (inclusive) in Python?
19 Answers
1...
Inserting data into a temporary table
After having created a temporary table and declaring the data types like so;
12 Answers
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C++ unordered_map using a custom class type as the key
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To be able to use std::unordered_map (or one of the other unordered associative containers) with a user-defined key-type, you need to define two things:
A hash function; this must be a class that overrides operator() and calcu...
jQuery ui dialog change title after load-callback
I like to change the title from an UI Dialog after i have submitted a form in this UI Dialog. So in the callback-function after load i should suggest, but i've tried and googled without result.
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Delete rows from a pandas DataFrame based on a conditional expression involving len(string) giving K
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When you do len(df['column name']) you are just getting one number, namely the number of rows in the DataFrame (i.e., the length of the column itself). If you want to apply len to each element in the column, use df['column name'].map(len). So try
df[df['column name'].map(len) < 2]
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How to change the commit author for one specific commit?
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Interactive rebase off of a point earlier in the history than the commit you need to modify (git rebase -i <earliercommit>). In the list of commits being rebased, change the text from pick to edit next to the hash of the one you want...
postgresql: INSERT INTO … (SELECT * …)
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As Henrik wrote you can use dblink to connect remote database and fetch result. For example:
psql dbtest
CREATE TABLE tblB (id serial, time integer);
INSERT INTO tblB (time) VALUES (5000), (2000);
psql postgres
CREATE TABLE tblA (id serial, time intege...