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How to copy a row and insert in same table with a autoincrement field in MySQL?
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select c1, c2, ...
from your_table
where id = 1
where c1, c2, ... are all the columns except id. If you want to explicitly insert with an id of 2 then include that in your INSERT column list and your SELECT:
insert into your_table (id, c1, c2, ...)
select 2, c1, c2, ...
from your_table
where i...
When to use dynamic vs. static libraries
...update is considered binary compatible with the original version.
Additionally dynamic libraries aren't necessarily loaded -- they're usually loaded when first called -- and can be shared among components that use the same library (multiple data loads, one code load).
Dynamic libraries were consid...
List all sequences in a Postgres db 8.1 with SQL
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The following query gives names of all sequences.
SELECT c.relname FROM pg_class c WHERE c.relkind = 'S';
Typically a sequence is named as ${table}_id_seq. Simple regex pattern matching will give you the table name.
To get last value of a sequence use the ...
round() for float in C++
... but there are others such as round-to-even, which is less biased and generally better if you're going to do a lot of rounding; it's a bit more complex to implement though.
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undefined reference to `WinMain@16'
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Building without that semi-documented flag one would have to more specifically tell the linker which subsystem value one desires, and some Windows API import libraries will then in general have to be specified explicitly:
C:\test> gnuc x.cpp -Wl,-subsystem,windows
C:\test> objdump -x a.exe...
Adding a new value to an existing ENUM Type
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It's worth mentioning that this can all be done in a single transaction, so it's mostly safe to do it in a production database.
– David Leppik
Jul 8 '11 at 20:41
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ImportError in importing from sklearn: cannot import name check_build
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Worked for me after installing scipy.
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What does the Q_OBJECT macro do? Why do all Qt objects need this macro?
I just started using Qt and noticed that all the example class definitions have the macro Q_OBJECT as the first line. What is the purpose of this preprocessor macro?
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What does __FILE__ mean in Ruby?
I see this all the time in Ruby:
4 Answers
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How to run code when a class is subclassed? [duplicate]
...- Watcher subclasses type, not object. 2 - SuperClass has no superclass at all, not object. I'm just so used to writing down object as a superclass for every class I defined that I somehow missed it that this code was using something else. Although there doesn't seem to be any harm in making SuperCl...