Orderby() not ordering numbers correctly c#
Int32.Parse is not supported by the LinqToSql translator. Convert.ToInt32 is supported. http://msdn.microsoft.com/en-us/library/sf1aw27b.aspx http://msdn.microsoft.com/en-us/library/bb882655.aspx
sql-order-by
ORDER BY NULL in MySQL
It’s for performance; adding ORDER BY NULL after a GROUP BY clause will make your query faster. An explanation, from the manual: By default, MySQL sorts all GROUP BY col1, col2, … queries as if you specified ORDER BY col1, col2, … in the query as well. If you include an explicit ORDER BY clause … Read more
ORDER BY ASC with Nulls at the Bottom
Only 1 minute after asking the question I found my answer. In the order by clause use case to make nulls have a higher value than anything else: ORDER BY (CASE WHEN districts.id IS NULL then 1 ELSE 0 END),districts.name, schools.name;
Hibernate order by with nulls last
This feature has been implemented during Hibernate 4.2.x and 4.3.x releases as previously mentioned. It can be used as for example: Criteria criteria = …; criteria.addOrder( Order.desc( “name” ).nulls(NullPrecedence.FIRST) ); Hibernate v4.3 javadocs are less omissive here.
How do I order a Group result, in Linq?
Just add the orderby clause 😉 from a in Audits join u in Users on a.UserId equals u.UserId group a by a.UserId into g let score = g.Sum(x => x.Score) orderby score descending select new { UserId = g.Key, Score = score };
Varchar to number conversion for sorting
Use: order by cast(column as unsigned) asc
Postgres: left join with order by and limit 1
Use a dependent subquery with max() function in a join condition. Something like in this example: SELECT * FROM companies c LEFT JOIN relationship r ON c.company_id = r.company_id AND r.”begin” = ( SELECT max(“begin”) FROM relationship r1 WHERE c.company_id = r1.company_id ) INNER JOIN addresses a ON a.address_id = r.address_id demo: http://sqlfiddle.com/#!15/f80c6/2
MySQL indices and order
Index order matters when your query conditions only apply to PART of the index. Consider: SELECT * FROM table WHERE first_name=”john” AND last_name=”doe” SELECT * FROM table WHERE first_name=”john” SELECT * FROM table WHERE last_name=”doe” If your index is (first_name, last_name) queries 1 and 2 will use it, query #3 won’t. If your index is … Read more
SQL Server UNION – What is the default ORDER BY Behaviour
There is no default order. Without an Order By clause the order returned is undefined. That means SQL Server can bring them back in any order it likes. EDIT: Based on what I have seen, without an Order By, the order that the results come back in depends on the query plan. So if there … Read more
Preserving ORDER BY in SELECT INTO
I know this is a bit old, but I needed to do something similar. I wanted to insert the contents of one table into another, but in a random order. I found that I could do this by using select top n and order by newid(). Without the ‘top n’, order was not preserved and … Read more