大约有 47,000 项符合查询结果（耗时：0.0443秒） [XML]
jQuery: Best practice to populate drop down?
...emory (with a string variable) first and then append this string to parent select control should be more efficient, because this will cause only once page layout
– Wint
Jul 2 '15 at 14:41
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MySQL get the date n days ago as a timestamp
...
DATE_SUB will do part of it depending on what you want
mysql> SELECT DATE_SUB(NOW(), INTERVAL 30 day);
2009-06-07 21:55:09
mysql> SELECT TIMESTAMP(DATE_SUB(NOW(), INTERVAL 30 day));
2009-06-07 21:55:09
mysql> SELECT UNIX_TIMESTAMP(DATE_SUB(NOW(), INTERVAL 30 day));
1244433347
...
MySQL dump by query
...
not mysqldump, but mysql cli...
mysql -e "select * from myTable" -u myuser -pxxxxxxxxx mydatabase
you can redirect it out to a file if you want :
mysql -e "select * from myTable" -u myuser -pxxxxxxxx mydatabase > mydumpfile.txt
Update:
Original post asked if...
Using async/await for multiple tasks
...ything but waiting.
int[] ids = new[] { 1, 2, 3, 4, 5 };
Task.WaitAll(ids.Select(i => DoSomething(1, i, blogClient)).ToArray());
On the other hand, the above code with WaitAll also blocks the threads and your threads won't be free to process any other work till the operation ends.
Recommende...
Cause of a process being a deadlock victim
I have a process with a Select which takes a long time to finish, on the order of 5 to 10 minutes. I am currently not using NOLOCK as a hint to the MS SQL database engine. At the same time we have another process doing updates and inserts into the same database and same tables. The first pr...
MySQL: Transactions vs Locking Tables
...ransactions vs locking tables to ensure database integrity and make sure a SELECT and UPDATE remain in sync and no other connection interferes with it. I need to:
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JPA : How to convert a native query result set to POJO class collection
...e done with an entity.
For instance:
Query query = em.createNativeQuery("SELECT name,age FROM jedi_table", Jedi.class);
@SuppressWarnings("unchecked")
List<Jedi> items = (List<Jedi>) query.getResultList();
But in this case, Jedi, must be a mapped entity class.
An alternative to avoi...
Throwing the fattest people off of an overloaded airplane.
...uch better. I use something quite like this for a recommendation engine (I select the top 200 items from a list of several million). I typically end up with only 50,000 or 70,000 items actually added to the heap.
I suspect that you'll see something quite similar: the majority of your candidates wil...
Checkbox for nullable boolean
...ents your null, whatever the semantics of null means. You could use a <select><option> drop down list to save real estate, but the user has to click twice and the choices aren't nearly as instantaneously clear.
1 0 null
True False Not Set
Yes No Undecided
Male Fema...
SQL Server : GROUP BY clause to get comma-separated values [duplicate]
...
try this:
SELECT ReportId, Email =
STUFF((SELECT ', ' + Email
FROM your_table b
WHERE b.ReportId = a.ReportId
FOR XML PATH('')), 1, 2, '')
FROM your_table a
GROUP BY ReportId
SQL fiddle demo
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