大约有 48,000 项符合查询结果（耗时：0.0365秒） [XML]
ActiveRecord, has_many :through, and Polymorphic Associations
...u're looking for.
class Widget < ActiveRecord::Base
has_many :widget_groupings
has_many :people, :through => :widget_groupings, :source => :grouper, :source_type => 'Person'
has_many :aliens, :through => :widget_groupings, :source => :grouper, :source_type => 'Alien'
end...
Multiple submit buttons on HTML form – designate one button as default [duplicate]
... Works great, thanks! I'd just add that if you want the button group to still float left, just enclose the "buttons" id element in a float left div, and then your buttons will be reordered with Next coming after Previous as desired, but the button group will remain floated left.
...
RegEx for matching UK Postcodes
...-Za-z]{2})$
To fix this issue, both options should be wrapped in another group (or non-capturing group) and the anchors placed around that:
^(([Gg][Ii][Rr] 0[Aa]{2})|((([A-Za-z][0-9]{1,2})|(([A-Za-z][A-Ha-hJ-Yj-y][0-9]{1,2})|(([AZa-z][0-9][A-Za-z])|([A-Za-z][A-Ha-hJ-Yj-y][0-9]?[A-Za-z])))) [0-9]...
What is the difference between svg's x and dx attribute?
...nd("line").attr('x1', 0).attr('x2', 500).attr('y1', 200).attr('y2', 200);
group = svg.selectAll("g")
.data(dataset)
.enter()
.append("g");
// Without the dy=0.35em offset
group.append("text")
.text("My text")
.attr("x",function (d) {return d;})
.attr("y",100)
.attr("tra...
How to make Eclipse behave well in the Windows 7 taskbar?
...g multiple Eclipses while each having their own Application ID, and making grouping of icons work as expected. The answer here does provide a reference to the underlying System.AppUserModel.ID property.
Here's a quick HOWTO:
Do the -vm setting as plenty of people here have mentioned
Run the eclip...
RESTful on Play! framework
...s that play framework did not recognize the application/json content type: groups.google.com/group/play-framework/browse_thread/thread/…
– Gary
Dec 28 '10 at 17:03
...
Why do table names in SQL Server start with “dbo”?
... [EnterSchemaNameHere] AUTHORIZATION [dbo]
You can use them to logically group your tables, for example by creating a schema for "Financial" information and another for "Personal" data. Your tables would then display as:
Financial.BankAccounts
Financial.Transactions
Personal.Address
Rather than ...
Showing data values on stacked bar chart in ggplot2
...n_stack() and position_fill() now stack values in the reverse order of the grouping, which makes the default stack order match the legend."
Answer valid for older versions of ggplot:
Here is one approach, which calculates the midpoints of the bars.
library(ggplot2)
library(plyr)
# calculate mi...
Get size of all tables in database
... NOT LIKE 'dt%'
AND t.is_ms_shipped = 0
AND i.OBJECT_ID > 255
GROUP BY
t.Name, s.Name, p.Rows
ORDER BY
TotalSpaceMB DESC, t.Name
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COUNT DISTINCT with CONDITIONS
...agTbl] AS B WHERE A.[Tag]=B.[Tag] AND B.[ID]>0)
from [TagTbl] AS A GROUP BY A.[Tag]
The first field will be the tag the second will be the whole count the third will be the positive ones count.
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