大约有 43,000 项符合查询结果（耗时：0.0437秒） [XML]
When to use a View instead of a Table?
...
Oh there are many differences you will need to consider
Views for selection:
Views provide abstraction over tables. You can add/remove fields easily in a view without modifying your underlying schema
Views can model complex joins easily.
Views can hide database-specific stuff from you. E....
Is the 'override' keyword just a check for a overridden virtual method?
...of different prototypes, only irregularities like missing const or writing char instead of int, etc.
– legends2k
Oct 20 '13 at 13:07
1
...
How to get database structure in MySQL via query
...CHEMA.TABLES table. It contains metadata about all your tables.
Example:
SELECT * FROM `INFORMATION_SCHEMA`.`TABLES`
WHERE TABLE_NAME LIKE 'table1'
The advantage of this over other methods is that you can easily use queries like the one above as subqueries in your other queries.
...
Show an image preview before upload
... code snippet in the HTML example below filters out images from the user's selection and renders selected files into multiple thumbnail previews:
function handleFileSelect(evt) {
var files = evt.target.files;
// Loop through the FileList and render image files as thumbnails.
fo...
Ignoring time zones altogether in Rails and PostgreSQL
...n parameter before being displayed to the client.
Example (in psql):
db=# SELECT timestamptz '2012-03-05 20:00+03';
timestamptz
------------------------
2012-03-05 18:00:00+01
What happened here?
I chose an arbitrary time zone offset +3 for the input literal. To Postgres, this is just one o...
How to set cursor position in EditText?
...
Where position is an int:
editText1.setSelection(position)
share
|
improve this answer
|
follow
|
...
How do I directly modify a Google Chrome Extension File? (.CRX)
... remove the _metadata folder.
From chrome://extensions in Developer mode select Load unpacked extension... and select your copied extension folder, if it contains a subfolder this is named by the version, select this version folder where there is a manifest file, this file is necessary for Chrome....
How can I print literal curly-brace characters in python string and also use .format on it?
...ying to format a small JSON for some purposes, like this: '{"all": false, "selected": "{}"}'.format(data) to get something like {"all": false, "selected": "1,2"}
It's pretty common that the "escaping braces" issue comes up when dealing with JSON.
I suggest doing this:
import json
data = "1,2"
my...
How to enable NSZombie in Xcode?
...cheme".
To edit the scheme and turn on zombies:
In the "Product" menu, select "Edit Scheme".
Go to the "Run Foo.app" stage in the left panel, and the "Arguments" tab on the right.
Add NSZombieEnabled to the "Environment Variables" section and set the value to YES, as you could in Xcode 3.
In...
Is there a way to create xxhdpi, xhdpi, hdpi, mdpi and ldpi drawables from a large scale image?
...er:
To use it after installed, right click your res/drawable folder and select New > Batch Drawable Import:
Then select your image via the + button and set the Resolution to be xxhdpi (or whatever the resolution of your source image is).
...