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Generate random int value from 3 to 6
Is it possible in Microsoft SQL Server generate random int value from Min to Max (3-9 example, 15-99 e.t.c)
10 Answers
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Get records with max value for each group of grouped SQL results
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There's a super-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 r...
SQL to find the number of distinct values in a column
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An sql sum of column_name's unique values and sorted by the frequency:
SELECT column_name, COUNT(*) FROM table_name GROUP BY column_name ORDER BY 2 DESC;
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select、poll、epoll之间的区别总结[整理] - C/C++ - 清泛网 - 专注C/C++及内核技术
...就行了，这节省了大量的CPU时间。这就是回调机制带来的性能提升。
（2）select，poll每次调用都要把fd集合从用户态往内核态拷贝一次，并且要把current往设备等待队列中挂一次，而epoll只要一次拷贝，而且把current往等待队列上...
Turning a Comma Separated string into individual rows
I have a SQL Table like this:
16 Answers
16
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How to select unique records by SQL
...Your data seems to indicate the minimum data value so in this instance for SQL Server.
SELECT item, min(data)
FROM table
GROUP BY item
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What's the difference between INNER JOIN, LEFT JOIN, RIGHT JOIN and FULL JOIN? [duplicate]
...nce between INNER JOIN , LEFT JOIN , RIGHT JOIN and FULL JOIN
in MySQL ?
3 Answers
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What's the hardest or most misunderstood aspect of LINQ? [closed]
...a mistaken impression of. I won't be specifically talking about LINQ to SQL or the Entity Framework except as examples of how queries can be executed remotely using expression trees (and usually IQueryable ).
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SQL function as default parameter value?
...ET @currentDate = COALESCE(@currentDate,GETDATE())
– SQLMenace
Jan 22 '09 at 20:32
I was using that previously. "I was...
Insert text with single quotes in PostgreSQL
...uotes or multiple layers of escaping, you can avoid quoting hell in PostgreSQL with dollar-quoted strings:
'escape '' with '''''
$$escape ' with ''$$
To further avoid confusion among dollar-quotes, add a unique token to each pair:
$token$escape ' with ''$token$
Which can be nested any number of...