大约有 41,000 项符合查询结果（耗时：0.0290秒） [XML]
Find rows with multiple duplicate fields with Active Record, Rails & Postgres
...
Tested & Working Version
User.select(:first,:email).group(:first,:email).having("count(*) > 1")
Also, this is a little unrelated but handy. If you want to see how times each combination was found, put .size at the end:
User.select(:first,:email).gro...
LINQ Using Max() to select a single row
I'm using LINQ on an IQueryable returned from NHibernate and I need to select the row with the maximum value(s) in a couple of fields.
...
MySQL: Selecting multiple fields into multiple variables in a stored procedure
Can I SELECT multiple columns into multiple variables within the same select query in MySQL?
3 Answers
...
Select the values of one property on all objects of an array in PowerShell
...
I think you might be able to use the ExpandProperty parameter of Select-Object.
For example, to get the list of the current directory and just have the Name property displayed, one would do the following:
ls | select -Property Name
This is still returning DirectoryInfo or FileInfo obje...
Entity framework linq query Include() multiple children entities
...ch allows the required depth of eager loading to be specified by providing Select expressions to the appropriate depth:
using System.Data.Entity; // NB!
var company = context.Companies
.Include(co => co.Employees.Select(emp => emp.Employee_Car))
.Inc...
How to create a WPF UserControl with NAMED content
... string[] names = e.NewValue.ToString().Split(new char[] { ',' });
if (d is FrameworkElement)
{
((FrameworkElement)d).Name = names[0];
Type t = Type.GetTy...
LINQ query to select top five
...
var list = (from t in ctn.Items
where t.DeliverySelection == true && t.Delivery.SentForDelivery == null
orderby t.Delivery.SubmissionDate
select t).Take(5);
share
...
SQL Logic Operator Precedence: And and Or
...te:
Declare @x tinyInt = 1
Declare @y tinyInt = 0
Declare @z tinyInt = 0
Select Case When @x=1 OR @y=1 And @z=1 Then 'T' Else 'F' End -- outputs T
Select Case When (@x=1 OR @y=1) And @z=1 Then 'T' Else 'F' End -- outputs F
For those who like to consult references (in alphabetic order):
Microso...
resizes wrong; appears to have unremovable `min-width: min-content`
I have a <select> where one of its <option> ’s text values is very long. I want the <select> to resize so it is never wider than its parent, even if it has to cut off its displayed text. max-width: 100% should do that.
...
what is the difference between GROUP BY and ORDER BY in sql
... SUM, COUNT, AVG, etc).
TABLE:
ID NAME
1 Peter
2 John
3 Greg
4 Peter
SELECT *
FROM TABLE
ORDER BY NAME
=
3 Greg
2 John
1 Peter
4 Peter
SELECT Count(ID), NAME
FROM TABLE
GROUP BY NAME
=
1 Greg
1 John
2 Peter
SELECT NAME
FROM TABLE
GROUP BY NAME
HAVING Count(ID) > 1
=
Peter
...