大约有 45,000 项符合查询结果（耗时：0.0432秒） [XML]
Xcode iOS project only shows “My Mac 64-bit” but not simulator or device
...duct->Scheme->Edit Scheme...), and for some reason no executable was selected. I chose my app, saved and now I have my simulator and device options back.
share
|
improve this answer
|...
How can you determine how much disk space a particular MySQL table is taking up?
...
For a table mydb.mytable run this for:
BYTES
SELECT (data_length+index_length) tablesize
FROM information_schema.tables
WHERE table_schema='mydb' and table_name='mytable';
KILOBYTES
SELECT (data_length+index_length)/power(1024,1) tablesize_kb
FROM information_schema....
Why is there no tuple comprehension in Python?
...because tuple syntax and parenthesis are ambiguous
– Charles Salvia
Jun 5 '13 at 13:14
21
The dif...
How to drop columns by name in a data frame
..."z","u"))]
x y
1 1 2
2 2 3
3 3 4
4 4 5
5 5 6
Or, much simpler, use the select argument of the subset function : you can then use the - operator directly on a vector of column names, and you can even omit the quotes around the names !
R> subset(df, select=-c(z,u))
x y
1 1 2
2 2 3
3 3 4
4 4 ...
In Windows cmd, how do I prompt for user input and use the result in another command?
...
set /p choice= "Please Select one of the above options :"
echo '%choice%'
The space after = is very important.
share
|
improve this answer
...
Strings as Primary Keys in SQL Database [closed]
... Also keep in mind that there's often a very big difference between a CHAR and a VARCHAR when doing index comparisons
– Tom H
Feb 5 '09 at 20:42
7
...
SQLite - How do you join tables from different databases?
...s with keyword
.databases
Then you should be able to do the following.
select
*
from
db1.SomeTable a
inner join
db2.SomeTable b on b.SomeColumn = a.SomeColumn;
Note that "[t]he database names main and temp are reserved for the primary database and database to hold temporary tables a...
How to select multiple files with ?
How to select multiple files with <input type="file"> ?
9 Answers
9
...
OnChange event handler for radio button (INPUT type=“radio”) doesn't work as one value
...ame attribute myRadios to read the variable prev which holds the currently selected radio. A comparison is done within each click handler to decide if the clicked radio is the same as the one stored in prev and if not then the currently clicked radio is stored there. Within the click handler, you ha...
SQL - HAVING vs. WHERE
...ows; HAVING clause introduces a condition on aggregations, i.e. results of selection where a single result, such as count, average, min, max, or sum, has been produced from multiple rows. Your query calls for a second kind of condition (i.e. a condition on an aggregation) hence HAVING works correctl...