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How to get next/previous record in MySQL?
...want to be able to go from one to another by navigation via next/previous links. The problem is, that I don't know how to fetch record with nearest higher ID.
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What is the most efficient/elegant way to parse a flat table into a tree?
...eries, we can say that all popular SQL databases support recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentId = t.Id
)
SELECT * FROM MyTree;
I tested recursiv...
ActiveRecord.find(array_of_ids), preserving order
When you do Something.find(array_of_ids) in Rails, the order of the resulting array does not depend on the order of array_of_ids .
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How to express a NOT IN query with ActiveRecord/Rails?
Just to update this since it seems a lot of people come to this, if you are using Rails 4 look at the answers by Trung Lê` and VinniVidiVicci.
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List of all index & index columns in SQL Server DB
How do I get a list of all index & index columns in SQL Server 2005+? The closest I could get is:
30 Answers
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How to select where ID in Array Rails ActiveRecord without exception
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If it is just avoiding the exception you are worried about, the "find_all_by.." family of functions works without throwing exceptions.
Comment.find_all_by_id([2, 3, 5])
will work even if some of the ids don't exist. This works in the
user...
Possibility of duplicate Mongo ObjectId's being generated in two different collections?
... possible for the same exact Mongo ObjectId to be generated for a document in two different collections? I realize that it's definitely very unlikely, but is it possible?
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Does MongoDB's $in clause guarantee order
When using MongoDB's $in clause, does the order of the returned documents always correspond to the order of the array argument?
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Build tree array from flat array in javascript
...x json file that I have to handle with javascript to make it hierarchical, in order to later build a tree.
Every entry of the json has :
id : a unique id,
parentId : the id of the parent node (which is 0 if the node is a root of the tree)
level : the level of depth in the tree
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Mysql order by specific ID values
Is it possible to sort in mysql by "order by" using predefined set of column values (ID) like: order by (ID=1,5,4,3) so I would get record 1, 5, 4, 3 in that order out?
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