大约有 1,800 项符合查询结果（耗时：0.0253秒） [XML]
In SQL, how can you “group by” in ranges?
... as [score range], count(*) as [number of occurrences]
from (
select user_id,
case when score >= 0 and score< 10 then '0-9'
when score >= 10 and score< 20 then '10-19'
else '20-99' end as range
from scores) t
group by t.range
...
Relational table naming convention [closed]
...ll the time, and you want keys to stand out from data columns. Always use user_id, never id.
Note that this is not a table name used as a prefix, but a proper descriptive name for the component of the key: user_id is the column that identifies an user, not the id of the user table.
(Except of...
Rails params explained?
...user's browser requested
http://www.example.com/?vote[item_id]=1&vote[user_id]=2
then params[:vote] would be a hash, params[:vote][:item_id] would be "1" and params[:vote][:user_id] would be "2".
The Ruby on Rails params are the equivalent of the $_REQUEST array in PHP.
...
Using column alias in WHERE clause of MySQL query produces an error
...e`
FROM `users` LEFT OUTER JOIN `locations`
ON `users`.`id` = `locations`.`user_id`
WHERE SUBSTRING(`locations`.`raw`,-6,4) NOT IN #this is where the fake col is being used
(
SELECT `postcode` FROM `postcodes` WHERE `region` IN
(
'australia'
)
)
However, I guess this is very inefficient, sinc...
MySQL COUNT DISTINCT
...
Select
Count(Distinct user_id) As countUsers
, Count(site_id) As countVisits
, site_id As site
From cp_visits
Where ts >= DATE_SUB(NOW(), INTERVAL 1 DAY)
Group By site_id
...
PatternSyntaxException: Illegal Repetition when using regex in Java
...ce the error message: "Illegal repetition".
You should escape them: "\\{\"user_id\" : [0-9]*\\}".
And since you seem to be trying to parse JSON, I suggest you have a look at Jackson.
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impro...
Facebook access token server-side validation for iPhone app
...iphone-safari"
},
application: YOUR_APP_NAMESPACE,
user_id: USER_ID,
issued_at: 1366236791,
expires_at: 1371420791,
scopes: [ ]
}
}
If that token isn't from "your app" then it will return an error response.
...
How can I verify a Google authentication API access token?
...xxxxxxxxxxxx-xxxxxxxxxxxxxxxxxxxxxxxxxx.apps.googleusercontent.com",
"user_id": "xxxxxxxxxxxxxxxxxxxxxxx",
"scope": "https://www.googleapis.com/auth/userinfo.profile https://gdata.youtube.com",
"expires_in": 3340,
"access_type": "offline"
}
The scope is the given permission...
Does a UNIQUE constraint automatically create an INDEX on the field(s)?
...unique keys are in fact B-tree type indexes.
A composite index on (email, user_id) is enough, you don't need a separate index on email only - MySQL can use leftmost parts of a composite index. There may be some border cases where the size of an index can slow down your queries, but you should not w...
无法打包成apk - App应用开发 - 清泛IT社区，为创新赋能！
本帖最后由 wlf2201 于 2025-03-02 11:20 编辑
打包apk时候，出现服务器故障，无法保存文件，请稍候重试
程序写的比较大，几乎没有图片，500k稍微多点，新建立一个只有几个元件的小项目，可以顺利打包，怀疑时程序过大导致...