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linq query to return distinct field values from a list of objects
... it's easy - project to that with Select and then use the normal Distinct call.)
In MoreLINQ we have the DistinctBy operator which you could use:
var distinct = list.DistinctBy(x => x.typeID);
This only works for LINQ to Objects though.
You can use a grouping or a lookup, it's just somewhat ...
Count how many records are in a CSV Python?
...aranteed to be a fixed size, so the only way to count them is to read them all.
– Martijn Pieters♦
Apr 19 '13 at 15:55
1
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Java synchronized method lock on object, or method?
... anyway. That's a bit misleading. Synchronizing on the method is functionally equivalent to having a synchronized (this) block around the body of the method. The object "this" doesn't become locked, rather the object "this" is used as the mutex and the body is prevented from executing concurrentl...
How to use clock() in C++
How do I call clock() in C++ ?
7 Answers
7
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Adding :default => true to boolean in existing Rails column
...
change_column is a method of ActiveRecord::Migration, so you can't call it like that in the console.
If you want to add a default value for this column, create a new migration:
rails g migration add_default_value_to_show_attribute
Then in the migration created:
# That's the more generic way t...
Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?
...an work around it from within psql by executing the DDL statement conditionally:
SELECT 'CREATE DATABASE mydb'
WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'mydb')\gexec
The manual:
\gexec
Sends the current query buffer to the server, then treats each column of each row of the query's...
How to go about formatting 1200 to 1.2k in java
...ng, String> suffixes = new TreeMap<> ();
static {
suffixes.put(1_000L, "k");
suffixes.put(1_000_000L, "M");
suffixes.put(1_000_000_000L, "G");
suffixes.put(1_000_000_000_000L, "T");
suffixes.put(1_000_000_000_000_000L, "P");
suffixes.put(1_000_000_000_000_000_000L, "E");
}
publ...
Linq: What is the difference between Select and Where
...rable<A> in, IEnumerable<A> out
Select
returns something for all items in the source (projection / transformation). That something might be the items themselves, but are more usually a projection of some sort.
-> IEnumerable<A> in, IEnumerable<B> out
...
Does IMDB provide an API? [closed]
...lo.json (alternate)
Format: JSON-P
Caveat: It's in JSON-P format, and the callback parameter can not customised. To use it cross-domain you'll have to use the function name they choose (which is in the imdb${searchphrase} format). Alternatively, one could strip or replace the padding via a local pro...
Why doesn't ruby support method overloading?
...; end; # second argument has a default value
method(10)
# Now the method call can match the first one as well as the second one,
# so here is the problem.
So ruby needs to maintain one method in the method look up chain with a unique name.
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