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Get records with max value for each group of grouped SQL results
...uper-simple way to do this in mysql:
select *
from (select * from mytable order by `Group`, age desc, Person) x
group by `Group`
This works because in mysql you're allowed to not aggregate non-group-by columns, in which case mysql just returns the first row. The solution is to first order the data...
MVC pattern on Android
...code.
This is particularly useful when you use Mono to share the model in order to develop cross-platform applications.
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How does password salt help against a rainbow table attack?
...the salt.
You always have to store the salt with the password, because in order to validate what the user entered against your password database, you have to combine the input with the salt, hash it and compare it to the stored hash.
Security of the hash
Now somebody with a rainbow table could rev...
Random row from Linq to Sql
...de...
throw new NotImplementedException();
}
}
Then just order by ctx.Random(); this will do a random ordering at the SQL-Server courtesy of NEWID(). i.e.
var cust = (from row in ctx.Customers
where row.IsActive // your filter
orderby ctx.Random()
...
Determine which MySQL configuration file is being used
...lt options"
Default options are read from the following files in the given order:
/etc/mysql/my.cnf ~/.my.cnf /usr/etc/my.cnf
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How to set Java environment path in Ubuntu
...'t work for me and the previous version remained as default. I changed the order of the path to export PATH=${JAVA_HOME}/bin:${PATH} and the version got updated. I think left to right priority works here.
– Ridhuvarshan
Dec 6 '17 at 9:00
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Why Does OAuth v2 Have Both Access and Refresh Tokens?
...cker requires the client id and secret in addition to the refresh token in order to gain an access token.
Having said that, because every call to both the authorization server and the resource server is done over SSL - including the original client id and secret when they request the access/refresh...
eval command in Bash and its typical uses
... as a text file, reads each line of text, and uses eval to execute them in order. That's essentially the same behavior as the bash source statement, which is what one would use, unless it was necessary to perform some kind of transformation (e.g. filtering or substitution) on the content of the impo...
Best design for a changelog / auditing database table? [closed]
...ed/updated/deleted a record
with ID=X in the table Foo and when?
So, in order to be able to answer such questions quickly (using SQL), we ended up having two additional columns in the audit table
object type (or table name)
object ID
That's when design of our audit log really stabilized (for a...
Hidden Features of SQL Server
...
A less known TSQL technique for returning rows in random order:
-- Return rows in a random order
SELECT
SomeColumn
FROM
SomeTable
ORDER BY
CHECKSUM(NEWID())
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