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How to select all records from one table that do not exist in another table?
...E b.Key IS NULL;
https://www.cloudways.com/blog/how-to-join-two-tables-mysql/
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Sending POST data in Android
... "6 - response !empty...");
//
JSONObject jRoot = new JSONObject(response);
JSONObject d = jRoot.getJSONObject("d");
int ResultType = d.getInt("ResultType");
Log.e("ResultType", ResultType + "");
if (Re...
Why are joins bad when considering scalability?
...
...except in MySQL, which seems to have performance problems with large numbers of joins regardless of how your indexes look. Or at least it has in the past.
– Powerlord
Apr 12 '10 at 17:53
...
Getting root permissions on a file inside of vi? [closed]
...
If you need root privileges to save a new file, replace % with the name (including path) of the new file.
– gvkv
Aug 10 '10 at 0:47
...
Cleaner way to do a null check in C#? [duplicate]
...public static class Helper
{
public static bool IsNull<T>(this T root,Expression<Func<T, object>> getter)
{
var visitor = new IsNullVisitor();
visitor.CurrentObject = root;
visitor.Visit(getter);
return visitor.IsNull;
}
}
class Program
...
MongoDB - admin user not authorized
...ad around the same issue, and everything worked after I set the role to be root when adding the first admin user.
use admin
db.createUser(
{
user: 'admin',
pwd: 'password',
roles: [ { role: 'root', db: 'admin' } ]
}
);
exit;
If you have already created the admin user, you can chan...
How do I test a file upload in rails?
...ctionDispatch::Http::UploadedFile.new({
:tempfile => File.new(Rails.root.join("test/fixtures/files/test.jpg"))
})
assert model.valid?
This way you can use the same methods you are using in your validations (as for example tempfile).
...
How to choose the id generation strategy when using JPA and Hibernate
...table. Do not use in a cluster.
identity
supports identity columns in DB2, MySQL, MS SQL Server, Sybase and HypersonicSQL. The returned identifier is of type long, short or int.
sequence
uses a sequence in DB2, PostgreSQL, Oracle, SAP DB, McKoi or a generator in Interbase. The returned identifier is...
ListCtrl 重绘（Custom Draw） - C/C++ - 清泛网 - 专注C/C++及内核技术
...处理＂重绘过程＂中所有的脏活了。
这篇文章的焦点是如何在一个LISTCTRL控件上使用Custom Draw消息。究其原因，一部分是因为我已经在我的工作上使用了Custom Draw有一段时间了，我很熟悉它。另一个原因是这个机制确实是非常好...
Python in Xcode 4+?
...at section by clicking on the triangle pointing to the right.
Type in $(SRCROOT)/ (or $(SOURCE_ROOT)/) and then the name of the Python file you want to test. Remember, the Python program must be in the project folder. Otherwise, you will have to type out the full path (or relative path if it's in a ...