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jQuery: Check if div with certain class name exists
...presumably because it changes the native features jQuery can use to do the selection. Here's a test case where the div exists, and here's one where it doesn't exist.
– T.J. Crowder
Apr 26 '11 at 6:10
...
内存优化总结:ptmalloc、tcmalloc和jemalloc - 操作系统(内核) - 清泛网 - ...
... 总共32个vcpu。 16个table，每个5M row。
OLTP_RO测试包含5个select查询：select_ranges, select_order_ranges, select_distinct_ranges, select_sum_ranges,
可以看到在多核心或者多线程的场景下， jemalloc和tcmalloc带来的tps增加非常明显。
参考资料
glibc...
iOS - Dismiss keyboard when touching outside of UITextField
... the view, and then call resign first responder on the UITextField on it's selector.
The code:
In viewDidLoad
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dismissKeyboard)];
[self.view addGestureRecognizer:tap];
In dismissKeyboard:
-(void)...
How do I center a window onscreen in C#?
...
Using the Property window
Select form → go to property window → select "start position" → select whatever the place you want.
Programmatically
Form form1 = new Form();
form1.StartPosition = FormStartPosition.CenterScreen;
form1.ShowDialog();
...
How to rename items in values() in Django?
... a bit hacky, but you could use the extra method:
MyModel.objects.extra(
select={
'renamed_value': 'cryptic_value_name'
}
).values(
'renamed_value'
)
This basically does SELECT cryptic_value_name AS renamed_value in the SQL.
Another option, if you always want the renamed version but the d...
How to access a mobile's camera from a web app?
...re="capture" (Boolean) . The attribute is used to force capture instead of selecting from the library. See the spec and Correct Syntax for HTML Media Capture
– Octavian Naicu
Nov 9 '16 at 15:56
...
How can I match on an attribute that contains a certain string?
I am having a problem selecting nodes by attribute when the attributes contains more than one word. For example:
10 Answer...
Is there a performance difference between CTE , Sub-Query, Temporary Table or Table Variable?
...ur question. If you click on the link you will see the reasons those users selected.
– Aaron Bertrand
Jun 23 '12 at 17:13
...
MySQL check if a table exists without throwing an exception
...
If you're using MySQL 5.0 and later, you could try:
SELECT COUNT(*)
FROM information_schema.tables
WHERE table_schema = '[database name]'
AND table_name = '[table name]';
Any results indicate the table exists.
From: http://www.electrictoolbox.com/check-if-mysql-table-exis...
Hibernate JPA Sequence (non-Id)
... an entity which has defined generated properties, it immediately issues a select afterwards to retrieve the generated values."
For properties generated on insert only, your property mapping (.hbm.xml) would look like:
<property name="foo" generated="insert"/>
For properties generated on i...