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Extract a dplyr tbl column as a vector
...2 3.62 3.54 4.11
A nice way to do this in v0.2 of dplyr:
iris2 %>% select(Species) %>% collect %>% .[[5]]
Or if you prefer:
iris2 %>% select(Species) %>% collect %>% .[["Species"]]
Or if your table isn't too big, simply...
iris2 %>% collect %>% .[["Species"]]
...
IN clause and placeholders
...mes = { "name1", "name2" }; // do whatever is needed first
String query = "SELECT * FROM table"
+ " WHERE name IN (" + makePlaceholders(names.length) + ")";
Cursor cursor = mDb.rawQuery(query, names);
Just make sure to pass exactly as many values as places. The default maximum limit of host pa...
C#: How to convert a list of objects to a list of a single property of that object?
...
List<string> firstNames = people.Select(person => person.FirstName).ToList();
And with sorting
List<string> orderedNames = people.Select(person => person.FirstName).OrderBy(name => name).ToList();
...
Why does HTML think “chucknorris” is a color?
...om the blog post, we get the following:
Replace all nonvalid hexadecimal characters with 0's
chucknorris becomes c00c0000000
Pad out to the next total number of characters divisible by 3 (11 -> 12)
c00c 0000 0000
Split into three equal groups, with each component representing the correspond...
Is the LIKE operator case-sensitive with MSSQL Server?
...en-us/library/ms144250(v=sql.105).aspx
(a) To check a instance collation
select serverproperty('collation')
(b) To check a database collation
select databasepropertyex('databasename', 'collation') sqlcollation
(c) To create a database using a different collation
create database exampledataba...
IIS - 401.3 - Unauthorized
... configuration of your site, modify the "Anonymous authentication" line by selecting "Identity of the application pool" instead of "Specific user".
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Open directory dialog
I want the user to select a directory where a file that I will then generate will be saved. I know that in WPF I should use the OpenFileDialog from Win32, but unfortunately the dialog requires file(s) to be selected - it stays open if I simply click OK without choosing one. I could "hack up" the f...
SQL Server Linked Server Example Query
...a Linked Server in SSMS Object Explorer, right-click, and Script Table as, SELECT To, and New Query Editor Window. The resulting SELECT statement will include the correct, fully-qualified path to the table. I had a mystery database qualifier in working with Sybase and this gave me the correct name.
...
What is the purpose of base 64 encoding and why it used in HTTP Basic Authentication?
...oding. It's a way of representing binary data using only printable (text) characters.
See this paragraph from the wikipedia page for HTTP Basic Authentication:
While encoding the user name and password with the Base64 algorithm typically makes them unreadable by the naked eye, they are as easi...
Length of an integer in Python
...h of an integer.
def libc_size(i):
return libc.snprintf(buf, 100, c_char_p(b'%i'), i) # equivalent to `return snprintf(buf, 100, "%i", i);`
def str_size(i):
return len(str(i)) # Length of `i` as a string
def math_size(i):
return 1 + math.floor(math.log10(i)) # 1 + floor of log10 of ...