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The differences between .build, .create, and .create! and when should they be used?
So I've been seeing people using .build , .create , and .create! within their controllers more and more lately. What's the difference from just using .new and passing the param'd object and then .save ? Are there pros and cons? Does using these other methods offer benefits?
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mysql Foreign key constraint is incorrectly formed error
I have two tables, table1 is the parent table with a column ID and table2 with a column IDFromTable1 (not the actual name) when I put a FK on IDFromTable1 to ID in table1 I get the error Foreign key constraint is incorrectly formed error . I would like to delete table 2 record if tab...
Importance of varchar length in MySQL table
...serted dynamically. Because I can not be certain of the length of strings and do not want them cut off, I make them varchar(200) which is generally much bigger than I need. Is there a big performance hit in giving a varchar field much more length than necessary?
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switch case statement error: case expressions must be constant expression
...ning eclipse gave me an error underlining the case statements in color red and says: case expressions must be constant expression, it is constant I don't know what happened. Here's my code below:
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How to squash all git commits into one?
... keep all the commit messages you could first do git log > original.log and then edit that for your initial commit message in the new repository:
rm -rf .git
git init
git add .
git commit
or
git log > original.log
# edit original.log as desired
rm -rf .git
git init
git add .
git commit -F ...
Progress indicator during pandas operations
I regularly perform pandas operations on data frames in excess of 15 million or so rows and I'd love to have access to a progress indicator for particular operations.
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Forward host port to docker container
...cker container access ports opened by the host? Concretely I have MongoDB and RabbitMQ running on the host and I'd like to run a process in a Docker container to listen to the queue and (optionally) write to the database.
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How to check if command line tools is installed
...as it appears in the Applications directory.
There are also the xcodebuild and xcode-select files in /usr/bin
I need to know if the command line tools is installed.
Is there a command for it?
What can I do to see if XCode CLT is installed and if yes to find the version installed?
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How to exit from Python without traceback?
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You are presumably encountering an exception and the program is exiting because of this (with a traceback). The first thing to do therefore is to catch that exception, before exiting cleanly (maybe with a message, example given).
Try something like this in your main r...
The model backing the context has changed since the database was created
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I've changed my production db manually and turned off the migration and it works, Thanks
– Mohsen Afshin
Sep 10 '12 at 21:05
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