... If your cascading deletes nuke a product because it was a member of a category that was killed, then you've set up your foreign keys improperly. Given your example tables, you should have the following table setup: CREATE TABLE cate...

... Not only can you, but you have to make a special effort not to if you don't want to. :-) When the browser encounters a classic script tag when parsing the HTML, it stops parsing and hands over to the JavaScript interpreter, which run...

...to have them type-safe makes sense even in a language like Clojure. Just because we can't statically check type-safety doesn't mean that we want our code to randomly break, right?] The Expression Problem is, how do you actually provide such extensibility in a language? It turns out that for typica...

... SQLite, technically, has no data types, there are storage classes in a manifest typing system, and yeah, it's confusing if you're used to traditional RDBMSes. Everything, internally, is stored as text. Data types are coerced/converted into...

...lner are It supports polymorphic functions; for example, a function that can give you the length of the list independent of the type of the elements, or a function does a binary-tree lookup independent of the type of keys stored in the tree. Sometimes a function or value can have more than one typ...

...mbols not only saves time when doing comparisons, but also saves memory, because they are only stored once. Ruby Symbols are immutable (can't be changed), which makes looking something up much easier Short(ish) answer: Using symbols not only saves time when doing comparisons, but also saves memor...

I'm using Primefaces in a JSF 2 application. I have a <p:dataTable> , and instead of selecting rows, I want the user to be able to directly execute various actions on individual rows. For that, I have several <p:commandLink> s in the last column. ...

... displayed on the screen for the cell. Using .Text is usually a bad idea because you could get #### .Value2 gives you the underlying value of the cell (could be empty, string, error, number (double) or boolean) .Value gives you the same as .Value2 except if the cell was formatted as currency or da...

...} hadoop fs <args> FS relates to a generic file system which can point to any file systems like local, HDFS etc. So this can be used when you are dealing with different file systems such as Local FS, (S)FTP, S3, and others hadoop dfs <args> dfs is very specific to HDFS. wo...

... I down-voted this answer because the right answer to the general question is: isinstance(ele, collections.Mapping). It works for dict(), collections.OrderedDict(), and collections.UserDict(). The example in the question is specific enough for Padriac's...