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Using LIMIT within GROUP BY to get N results per group?
...ehavior of both quirks is not guaranteed. Revised answer as follows.
In MySQL 5.x you can use poor man's rank over partition to achieve desired result. Just outer join the table with itself and for each row, count the number of rows lesser than it. In the above case, lesser row is the one with high...
Dynamic LINQ OrderBy on IEnumerable / IQueryable
...example in the VS2008 Examples for Dynamic LINQ that allows you to use a sql-like string (e.g. OrderBy("Name, Age DESC")) for ordering. Unfortunately, the method included only works on IQueryable<T> . Is there any way to get this functionality on IEnumerable<T> ?
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Difference between Repository and Service Layer?
...Service could return only ones, user has access to.
In ASP.NET MVC + EF + SQL SERVER, I have this flow of communication:
Views <- Controllers -> Service layer -> Repository layer -> EF -> SQL Server
Service layer -> Repository layer -> EF This part operates on models.
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How important is the order of columns in indexes?
...hat I am illustrating in a very simple way. This isn't very unique or even SQL specific; B-tree indexing is pretty common across so many things.
– Nick Craver♦
Aug 23 '16 at 10:11
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How to make connection to Postgres via Node.js
...se, so I installed postgres and started a server with initdb /usr/local/pgsql/data , then I started that instance with postgres -D /usr/local/pgsql/data now how can I interact with this through node? For example, what would the connectionstring be, or how am I able to find out what it is.
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How do you track record relations in NoSQL?
I am trying to figure out the equivalent of foreign keys and indexes in NoSQL KVP or Document databases. Since there are no pivotal tables (to add keys marking a relation between two objects) I am really stumped as to how you would be able to retrieve data in a way that would be useful for normal we...
ROW_NUMBER() in MySQL
Is there a nice way in MySQL to replicate the SQL Server function ROW_NUMBER() ?
24 Answers
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How do I reset a sequence in Oracle?
In PostgreSQL , I can do something like this:
18 Answers
18
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Checkout one file from Subversion
... cd /tmp
$ svn co --depth empty http://svn.your.company.ca/training/trunk/sql
Run svn up to update specified file:
$ svn up http://svn.your.company.ca/training/trunk/sql/showSID.sql
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imp...
Is there a good reason I see VARCHAR(255) used so often (as opposed to another length)?
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@CharlesBretana: By "fake UTF-8" I mean MySQL's "utf8" encoding, which as I mentioned reserves (and is limited to) 3 bytes per character. This isn't a very good version of UTF-8; if you want decent UTF-8 in MySQL, you have to use its "utf8mb4" encoding. But people ...