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Unique constraint that allows empty values in MySQL
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183
Yes, you can do this. See the MySQL reference (version 5.5).
A UNIQUE index creates a cons...
MySQL “NOT IN” query
I wanted to run a simple query to throw up all the rows of Table1 where a principal column value is not present in a column in another table ( Table2 ).
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Why is the time complexity of both DFS and BFS O( V + E )
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Your sum
v1 + (incident edges) + v2 + (incident edges) + .... + vn + (incident edges)
can be rewritten as
(v1 + v2 + ... + vn) + [(incident_edges v1) + (incident_edges v2) + ... + (incident_edges vn)]
and the first group is O(N) w...
Why is null an object and what's the difference between null and undefined?
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21 Answers
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What is the meaning of the CascadeType.ALL for a @ManyToOne JPA association
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edited May 1 '13 at 18:25
answered Oct 23 '12 at 9:33
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Disable assertions in Python
...rt False"
Traceback (most recent call last):
File "<string>", line 1, in <module>
AssertionError
Note that by disable I mean it also does not execute the expression that follows it:
$ python -Oc "assert 1/0"
$ python -c "assert 1/0"
Traceback (most recent call last):
File "<st...
Access denied for user 'test'@'localhost' (using password: YES) except root user
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13 Answers
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Is there a Google Keep API? [closed]
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142
No there isn't. If you watch the http traffic and dump the page source you can see that there ...
The differences between .build, .create, and .create! and when should they be used?
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edited May 23 '17 at 10:31
Community♦
111 silver badge
answered Dec 31 '08 at 18:26
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How do I strip non alphanumeric characters from a string and keep spaces?
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189
Add spaces to the negated character group:
@search_query = @search_query.gsub(/[^0-9a-z ]/i, ...