大约有 5,883 项符合查询结果（耗时：0.0286秒） [XML]
Is there a way to get a collection of all the Models in your Rails app?
...
ActiveRecord::Base.connection.tables.map do |model|
model.capitalize.singularize.camelize
end
will return
["Article", "MenuItem", "Post", "ZebraStripePerson"]
Additional information If you want to call a method on the object name without model:stri...
Android Studio: how to attach Android SDK sources?
...for SDK is available only for API levels 14 and above.
UPDATE ( Based on stable release 3.2.1):
Google changes the approach of shipping the sources, so lets see what changed.
Go to the following location
Preferences -> Apperance & Behaviour -> System Settings -> Android SDK
Quite ...
JOIN two SELECT statement results
....[# Late], 0) AS [# Late]
FROM
(SELECT ks, COUNT(*) AS '# Tasks' FROM Table GROUP BY ks) t1
LEFT JOIN
(SELECT ks, COUNT(*) AS '# Late' FROM Table WHERE Age > Palt GROUP BY ks) t2
ON (t1.ks = t2.ks);
share
...
The entity type is not part of the model for the current context
...g(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Estate>().ToTable("Estate");
}
If your tables are not created on startup, this is why. You need to tell the DbContext about them in the OnModelCreating method override.
You can either do custom per-entity mappings here, or separate t...
How to sort a dataframe by multiple column(s)
...ices
order from base
arrange from dplyr
setorder and setorderv from data.table
arrange from plyr
sort from taRifx
orderBy from doBy
sortData from Deducer
Most of the time you should use the dplyr or data.table solutions, unless having no-dependencies is important, in which case use base::order.
...
Split delimited strings in a column and insert as new rows [duplicate]
...
Here is another way of doing it..
df <- read.table(textConnection("1|a,b,c\n2|a,c\n3|b,d\n4|e,f"), header = F, sep = "|", stringsAsFactors = F)
df
## V1 V2
## 1 1 a,b,c
## 2 2 a,c
## 3 3 b,d
## 4 4 e,f
s <- strsplit(df$V2, split = ",")
data.frame(V1 ...
SQLAlchemy ORDER BY DESCENDING?
...
from sqlalchemy import desc
someselect.order_by(desc(table1.mycol))
Usage from @jpmc26
share
|
improve this answer
|
follow
|
...
Correct way to use StringBuilder in SQL
...ink you've misquoted it, though; surely there aren't quotes around id2 and table?)
Note that the aim (usually) is to reduce memory churn rather than total memory used, to make life a bit easier on the garbage collector.
Will that take memory equal to using String like below?
No, it'll cause m...
Printing Lists as Tabular Data
...e 24
Bob 19
tabulate has many options to specify headers and table format.
print(tabulate([['Alice', 24], ['Bob', 19]], headers=['Name', 'Age'], tablefmt='orgtbl'))
| Name | Age |
|--------+-------|
| Alice | 24 |
| Bob | 19 |
2. PrettyTable: https://pypi.python.org/...
Can I use multiple “with”?
... + '%', X.[SQL]) > 0
) AS INC
)
And yes, you can reference common table expression inside common table expression definition. Even recursively. Which leads to some very neat tricks.
share
|
...