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PostgreSQL function for last inserted ID
In PostgreSQL, how do I get the last id inserted into a table?
10 Answers
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How to efficiently build a tree from a flat structure?
I have a bunch of objects in a flat structure. These objects have an ID and a ParentID property so they can be arranged in trees. They are in no particular order.
Each ParentID property does not necessarily matches with an ID in the structure. Therefore their could be several trees emerging ...
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...
Can an html element have multiple ids?
I understand that an id must be unique within an HTML/XHTML page.
18 Answers
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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 JOIN the most recent row only?
...changes made to the customer, i.e. when there's a change made a new row is inserted.
8 Answers
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What's the difference between an id and a class?
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ids must be unique where as class can be applied to many things. In CSS, ids look like #elementID and class elements look like .someClass
In general, use id whenever you want to refer to a specific element and class when you have a number of things that are all alike. For instance, ...
Oracle “(+)” Operator
I am checking some old SQL Statements for the purpose of documenting them and probably enhancing them.
4 Answers
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Can multiple different HTML elements have the same ID if they're different elements?
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No.
Element IDs should be unique within the entire document.
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Retrieving the last record in each group - MySQL
There is a table messages that contains data as shown below:
27 Answers
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