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MySQL error: key specification without a key length
...h as VARCHAR(512) will force MySQL to auto-convert the VARCHAR(512) to a SMALLTEXT datatype, which subsequently fails with error 1170 on key length if the column is used as primary key or unique or non-unique index. To solve this problem, specify a figure less than 256 as the size for VARCHAR field....
Why exactly is eval evil?
I know that Lisp and Scheme programmers usually say that eval should be avoided unless strictly necessary. I’ve seen the same recommendation for several programming languages, but I’ve not yet seen a list of clear arguments against the use of eval . Where can I find an account of the potentia...
Ruby: How to post a file via HTTP as multipart/form-data?
...o an HTTP POST that looks like an HMTL form posted from a browser. Specifically, post some text fields and a file field.
12...
Best practice for storing and protecting private API keys in applications [closed]
... time, this happens through an API key. For security purposes, services usually generate a public and private, often also referred to as secret, key. Unfortunately, in order to connect to the services, this private key must be used to authenticate and hence, probably be part of the application.
Nee...
Why does CSS work with fake elements?
... Why doesn't my professor want me to use made-up elements?
They are not allowed by the HTML specification
They might conflict with future standard elements with the same name
There is probably an existing HTML element that is better suited to the task
Also; why didn't he know that made-up el...
Matplotlib discrete colorbar
...ues to show up as grey
cmap = plt.cm.jet # define the colormap
# extract all colors from the .jet map
cmaplist = [cmap(i) for i in range(cmap.N)]
# force the first color entry to be grey
cmaplist[0] = (.5, .5, .5, 1.0)
# create the new map
cmap = mpl.colors.LinearSegmentedColormap.from_list(
...
What is the difference between IEqualityComparer and IEquatable?
...ted) IEqualityComparer<T> is an interface for an object (which is usually a lightweight class different from T) that provides comparison functions that operates on T
– rwong
Feb 22 at 16:40
...
How to add Action Bar from support library into PreferenceActivity?
...ected void onCreate(Bundle savedInstanceState) {
getDelegate().installViewFactory();
getDelegate().onCreate(savedInstanceState);
super.onCreate(savedInstanceState);
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(sa...
How can I read and parse CSV files in C++?
I need to load and use CSV file data in C++. At this point it can really just be a comma-delimited parser (ie don't worry about escaping new lines and commas). The main need is a line-by-line parser that will return a vector for the next line each time the method is called.
...
make_unique and perfect forwarding
... A make_unique function template does not itself guarantee exception safe calls. It relies on convention, that the caller uses it. In contrast, strict static type checking (which is the main diff between C++ and C) is built on the idea of enforcing safety, via types. And for that, make_unique can si...