大约有 43,000 项符合查询结果（耗时：0.0464秒） [XML]
Does a break statement break from a switch/select?
I know that switch / select statements break automatically after every case. I am wondering, in the following code:
6 Ans...
Reshaping data.frame from wide to long format
...
Here is another example showing the use of gather from tidyr. You can select the columns to gather either by removing them individually (as I do here), or by including the years you want explicitly.
Note that, to handle the commas (and X's added if check.names = FALSE is not set), I am also us...
How to alter SQL in “Edit Top 200 Rows” in SSMS 2008
...008 Management Studio, when I right click on a database table and choose " Select Top 100 Rows ", I can then e.g. easily add a "ORDER BY " statement to the SQL. That works fine .
...
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 ...
Why is an array not assignable to Iterable?
...able forces adding an iterator method, and arrays don't implement methods. char[] doesn't even override toString. Anyway, arrays of references should be considered less than ideal - use Lists. As dfa comments, Arrays.asList will do the conversion for you, explicitly.
(Having said that, you can call...
Postgres DB Size Command
..."pg_datbase" system table. Just apply the function to the names, as below.
select t1.datname AS db_name,
pg_size_pretty(pg_database_size(t1.datname)) as db_size
from pg_database t1
order by pg_database_size(t1.datname) desc;
If you intend the output to be consumed by a machine instead of a...
Ruby Arrays: select(), collect(), and map()
...re, to check the :qty key, you'd do something like the following:
details.select{ |item| item[:qty] != "" }
That will give you all items where the :qty key isn't an empty string.
official select documentation
share
...
Dump a mysql database to a plaintext (CSV) backup from the command line
... separated) files which can import into Excel, etc, quite easily:
% echo 'SELECT * FROM table' | mysql -B -uxxx -pyyy database
Alternatively, if you've got direct access to the server's file system, use SELECT INTO OUTFILE which can generate real CSV files:
SELECT * INTO OUTFILE 'table.csv'
...
Disable dragging an image from an HTML page
...
But this lead to the weird selection effect in FF atleast. Better still return false;
– Bhumi Singhal
Feb 22 '13 at 10:24
...
How do I select the “last child” with a specific class name in CSS? [duplicate]
How do I select the "last child" with the class name: list ?
6 Answers
6
...