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Delete sql rows where IDs do not have a match from another table
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Using LEFT JOIN/IS NULL:
DELETE b FROM BLOB b
LEFT JOIN FILES f ON f.id = b.fileid
WHERE f.id IS NULL
Using NOT EXISTS:
DELETE FROM BLOB
WHERE NOT EXISTS(SELECT NULL
FROM FILES f
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Pickle incompatibility of numpy arrays between Python 2 and 3
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This seems like some sort of incompatibility. It's trying to load a "binstring" object, which is assumed to be ASCII, while in this case it is binary data. If this is a bug in the Python 3 unpickler, or a "misuse" of the pickler by numpy, I don't know...
Unix command to find lines common in two files
I'm sure I once found a unix command which could print the common lines from two or more files, does anyone know its name? It was much simpler than diff .
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How to create a string with format?
I need to create a string with format which can convert int, long, double etc. types into string. Using Obj-C, I can do it via below way.
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In PHP, what is a closure and why does it use the “use” identifier?
I'm checking out some PHP 5.3.0 features and ran across some code on the site that looks quite funny:
6 Answers
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YYYY-MM-DD format date in shell script
...$(date) in my bash shell script, however, I want the date in YYYY-MM-DD format.
How do I get this?
13 Answers
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Dashed line border around UIView
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yourViewBorder.strokeColor = [UIColor blackColor].CGColor;
yourViewBorder.fillColor = nil;
yourViewBorder.lineDashPattern = @[@2, @2];
yourViewBorder.frame = yourView.bounds;
yourViewBorder.path = [UIBezierPath bezierPathWithRect:yourView.bounds].CGPath;
[yourView.layer addSublayer:yourViewBorder];...
Copying files from host to Docker container
I am trying to build a backup and restore solution for the Docker containers that we work with.
41 Answers
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Count occurrences of a char in a string using Bash
I need to count the number of occurrences of a char in a string using Bash.
7 Answers
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How to tell if a tag failed to load
...page's <head> , and I'd like to be able to tell whether the loading failed in some way -- a 404, a script error in the loaded script, whatever.
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