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how to emulate “insert ignore” and “on duplicate key update” (sql merge) with postgresql?
... two queries, one for INSERT and one for UPDATE (as an appropriate join/subselect of course - no need to write your main filter twice)
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Is there a way to access the “previous row” value in a SELECT statement?
...d to order by some column for this to be meaningful. Something like this:
select t1.value - t2.value from table t1, table t2
where t1.primaryKey = t2.primaryKey - 1
If you know how to order things but not how to get the previous value given the current one (EG, you want to order alphabetically) ...
Find rows with multiple duplicate fields with Active Record, Rails & Postgres
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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.
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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
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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...
Select the values of one property on all objects of an array in PowerShell
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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...
Convert from enum ordinal to enum type
...diamonds and clubs! A C programmer would allocate 1 byte for each: 'const char CLUBS=0;' etc... Yes,a HashMap lookup is O(1), but the memory and CPU overhead of a HashMap, in this case make it many orders of magnitude slower and resource hungry than calling .values() directly! No wonder Java is suc...
LINQ query to select top five
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var list = (from t in ctn.Items
where t.DeliverySelection == true && t.Delivery.SentForDelivery == null
orderby t.Delivery.SubmissionDate
select t).Take(5);
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Facebook Callback appends '#_=_' to Return URL
...h (or even
a server-side redirect of your own) to remove the offending
characters.
Source: https://developers.facebook.com/bugs/318390728250352/
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