大约有 40,000 项符合查询结果（耗时：0.0330秒） [XML]
Update Row if it Exists Else Insert Logic with Entity Framework
...);
}
context.SaveChanges();
If you can't decide existance of the object by its Id you must exectue lookup query:
var id = myEntity.Id;
if (context.MyEntities.Any(e => e.Id == id))
{
context.MyEntities.Attach(myEntity);
context.ObjectStateManager.ChangeObjectState(myEntity, EntityState...
Split column at delimiter in data frame [duplicate]
...andle the situations where there are different numbers of values separated by '|'. Of course, one has to deal with the result of rbind which may recycle for those rows with fewer elements. But the other solution would fail for such case.
– Yu Shen
Apr 17 '15 at...
How to set initial value and auto increment in MySQL?
...
Heh, time passes by... Sure, define it in CREATE TABLE if you are able to do that. The second "ALTER TABLE" part of answer implies that you have already created a table, and it is probably already deployed somewhere without proper index, whic...
How to Customize a Progress Bar In Android
... ProgressBar here in this example. I've achieved
this using ClipDrawable by clipping image with Animation.
A Drawable that clips another Drawable based on this Drawable's current level value. You can control how much the child Drawable gets clipped in width and height based on the level, as well...
Change the name of the :id parameter in Routing resources for Rails
...ram: :slug
# app/controllers/posts_controller.rb
# ...
@post = Post.find_by(slug: params[:slug])
# ...
As of the release of Rails 4, this functionality is documented in the Rails Guides.
Rails 3
Unfortunately, in Rails 3, the :key option for resources was removed, so you can no longer easily c...
Is it possible to rename a maven jar-with-dependencies?
...big daft name.
As a workaround, you can copy the assembly descriptor used by the jar-with-dependencies descriptor and modify the id.
This example would result in the assembly id being appended to the finalName, so if you need to have a name of region-full.jar, you can specify the finalName as regi...
“Insert if not exists” statement in SQLite
... imageUploader: {
brandingHtml: "Powered by \u003ca href=\"https://imgur.com/\"\u003e\u003csvg class=\"svg-icon\" width=\"50\" height=\"18\" viewBox=\"0 0 50 18\" fill=\"none\" xmlns=\"http://www.w3.org/2000/svg\"\u003e\u003cpath d=\"M46.1709 9.17788C46.1709 8.26454...
Calling a Fragment method from a parent Activity
...roid Fragments Dev Guide that an "activity can call methods in a fragment by acquiring a reference to the Fragment from FragmentManager, using findFragmentById() or findFragmentByTag() ."
...
Cannot insert explicit value for identity column in table 'table' when IDENTITY_INSERT is set to OFF
...wer, but on the other hand, someone have set the column to be incrementing by itself up on insert. In that case the table will keep track of the next free number, and you do not need to generate the OperationID by yourself. The new id can be fetched by SELECT SCOPE_IDENTITY().
–...
Ways to save Backbone.js model data?
...e are a few ways to do so. For example, you can set up your model instance by passing in a JSON OR use method called set() which takes a JSON object of attributes.
myDonut = new Donut({'flavor':'lemon', 'price':'0.75'});
mySecondHelping = new Donut();
mySecondHelping.set({'flavor':'plain', 'price':...