大约有 30,000 项符合查询结果（耗时：0.0370秒） [XML]
Add unique constraint to co<em>mem>bination of two colu<em>mem>ns
I have a table and, so<em>mem>ehow, the sa<em>mem>e person got into <em>mem>y Person table twice. Right now, the pri<em>mem>ary key is just an autonu<em>mem>ber but there are two other fields that exist that I want to force to be unique.
...
nodeValue vs innerHT<em>Mem>L and textContent. How to choose?
I'<em>mem> using plain js to alter the inner text of a label ele<em>mem>ent, and I wasn't sure on what grounds I should use innerHT<em>Mem>L or nodeValue or textContent. I don't need to create a new node or change the HT<em>Mem>L ele<em>mem>ents or anything — just replace the text. Here's an exa<em>mem>ple of the code:
...
When serving JavaScript files, is it better to use the application/javascript or application/x-javas
The whole question fits in the title. And to add so<em>mem>e context: I'<em>mem> not asking what is the best according to what the specs are saying, but rather what works the best given the <em>mem>ix of browsers deployed nowadays.
...
How do I write good/correct package __init__.py files
<em>Mem>y package has the following structure:
3 Answers
3
...
Why do you need to create a cursor when querying a sqlite database?
I'<em>mem> co<em>mem>pletely new to Python's sqlite3 <em>mem>odule (and SQL in general for that <em>mem>atter), and this just co<em>mem>pletely stu<em>mem>ps <em>mem>e. The abundant lack of descriptions of cursor objects (rather, their necessity) also see<em>mem>s odd.
...
Any difference between First Class Function and High Order Function
I'<em>mem> wondering whether/what difference between First Class Function and High Order Function .
6 Answers
...
Why is arr = [] faster than arr = new Array?
...
Further expanding on previous answers...
Fro<em>mem> a general co<em>mem>pilers perspective and disregarding V<em>Mem>-specific opti<em>mem>izations:
First, we go through the lexical analysis phase where we tokenize the code.
By way of exa<em>mem>ple, the following tokens <em>mem>ay be produced:
[]: ARRAY_I...
Why do we need <em>mem>essage brokers like Rabbit<em>Mem>Q over a database like PostgreSQL?
I a<em>mem> new to <em>mem>essage brokers like Rabbit<em>Mem>Q which we can use to create tasks / <em>mem>essage queues for a scheduling syste<em>mem> like Celery .
...
Backbone.View “el” confusion
...ire events you need to do your rendering work on the el. A views el is a DO<em>Mem> ele<em>mem>ent but it does not have to be a pre-existing ele<em>mem>ent. It will be created if you do not pull one fro<em>mem> your current page, but you will have to insert it into the page if you ever want to see it do anything.
An exa<em>mem>ple:
...
Convert blob URL to nor<em>mem>al URL
<em>Mem>y page generates a URL like this: "blob:http%3A//localhost%3A8383/568233a1-8b13-48b3-84d5-cca045ae384f" How can I convert it to a nor<em>mem>al address?
...