大约有 41,000 项符合查询结果（耗时：0.0341秒） [XML]
Select mySQL based only on month and year
...
SELECT * FROM projects WHERE YEAR(Date) = 2011 AND MONTH(Date) = 5
share
|
improve this answer
|
f...
Fastest way to check if a file exist using standard C++/C++11/C?
...r. This does not use many fancy features of C++:
bool is_file_exist(const char *fileName)
{
std::ifstream infile(fileName);
return infile.good();
}
share
|
improve this answer
|
...
JOIN queries vs multiple queries
...han several queries? (You run your main query, and then you run many other SELECTs based on the results from your main query)
...
Get records with max value for each group of grouped SQL results
...
There's a super-simple way to do this in mysql:
select *
from (select * from mytable order by `Group`, age desc, Person) x
group by `Group`
This works because in mysql you're allowed to not aggregate non-group-by columns, in which case mysql just returns the first row. T...
Rails 3: Get Random Record
...You can use the following trick on an indexed column (PostgreSQL syntax):
select *
from my_table
where id >= trunc(
random() * (select max(id) from my_table) + 1
)
order by id
limit 1;
share
|
...
Postgres manually alter sequence
...
The parentheses are misplaced:
SELECT setval('payments_id_seq', 21, true); # next value will be 22
Otherwise you're calling setval with a single argument, while it requires two or three.
...
Run PostgreSQL queries from the command line
...
psql -U username -d mydatabase -c 'SELECT * FROM mytable'
If you're new to postgresql and unfamiliar with using the command line tool psql then there is some confusing behaviour you should be aware of when you've entered an interactive session.
For example, ...
MySQL select 10 random rows from 600K rows fast
How can I best write a query that selects 10 rows randomly from a total of 600k?
26 Answers
...
IIS7 Permissions Overview - ApplicationPoolIdentity
...eplace this text below if it is named differently)
Open Windows Explorer
Select a file or directory.
Right click the file and select "Properties"
Select the "Security" tab
Click the "Edit" and then "Add" button
Click the "Locations" button and make sure you select the local machine. (Not the Windo...
Get a list of checked checkboxes in a div using jQuery
I want to get a list of names of checkboxes that are selected in a div with certain id. How would I do that using jQuery?
8...