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SQL Server: SELECT only the rows with MAX(DATE)
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For MySql you can do something like the following:
select OrderNO, PartCode, Quantity from table a
join (select ID, MAX(DateEntered) from table group by OrderNO) b on a.ID = b.ID
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Python recursive folder read
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Make sure you understand the three return values of os.walk:
for root, subdirs, files in os.walk(rootdir):
has the following meaning:
root: Current path which is "walked through"
subdirs: Files in root of type directory
files: Files in root (not in subdirs) of type other than directory...
Read/write to Windows registry using Java
...tatic final int KEY_READ = 0x20019;
private static final Preferences userRoot = Preferences.userRoot();
private static final Preferences systemRoot = Preferences.systemRoot();
private static final Class<? extends Preferences> userClass = userRoot.getClass();
private static final Method...
What does “Document-oriented” vs. Key-Value mean when talking about MongoDB vs Cassandra?
... of a database at the top level, then collections which are like tables in MySQL (for example) and then documents which are contained within the collection, like rows in MySQL. Each document has a field and a value where this is similar to columns and values in MySQL. Fields can be simple key / valu...
Python list directory, subdirectory, and files
...ncatenate the directory and file name:
for path, subdirs, files in os.walk(root):
for name in files:
print os.path.join(path, name)
Note the usage of path and not root in the concatenation, since using root would be incorrect.
In Python 3.4, the pathlib module was added for easier path...
Django CharField vs TextField
...nce among these three types", but AFAIK there are some differences in e.g. MySQL, so this is something to keep in mind.
A good rule of thumb is that you use CharField when you need to limit the maximum length, TextField otherwise.
This is not really Django-specific, also.
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zsh compinit: insecure directories
...u may need to update the owner of site-functions as well:
$ sudo chown -R root:root ./site-functions
On my machine (OSX 10.9), I do not need to do this but YMMV.
EDIT2: On OSX 10.11, only this worked:
$ cd /usr/local/share/
$ sudo chmod -R 755 zsh
$ sudo chown -R root:staff zsh
Also user:staf...
SQL statement to select all rows from previous day
...microsoft.com/en-us/library/ms189794.aspx) the question you link to is for MySql, which I guess works differently as you have found. You will find that SQL is not completely interchangeable, there are many differences like this between different vendors, especially regarding date handling.
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Django-Admin: CharField as TextArea
...form = BookForm
admin.site.register(Book, BookAdmin)
If you are using a MySQL DB, your column length will usually be autoset to 250 characters, so you will want to run an ALTER TABLE to change the length in you MySQL DB, so that you can take advantage of the new larger Textarea that you have in y...
Ukkonen's suffix tree algorithm in plain English
...ts.
What we are building, is basically like a search trie. So there
is a root node, edges going out of it leading to new nodes, and
further edges going out of those, and so forth
But: Unlike in a search trie, the edge labels are not single
characters. Instead, each edge is labeled using a pair of ...