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how to emulate “insert ignore” and “on duplicate key update” (sql merge) with postgresql?
...skipped if it would violate a primary/unique key constraint. For instance, MySQL has INSERT IGNORE .
11 Answers
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INSERT … ON DUPLICATE KEY (do nothing)
... uses resources for the second action.
Use INSERT IGNORE ...,
Negative : MySQL will not show any errors if something goes wrong, so you cannot handle the errors. Use it only if you don’t care about the query.
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“use database_name” command in PostgreSQL
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If I'm not mistaken, databases in MySQL are more akin to schemas in PostgreSQL -- you can switch between those, but DBs in PostgreSQL are a whole different ballgame.
– mpen
May 10 '12 at 3:40
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How do you do a limit query in JPQL or HQL?
In Hibernate 3, is there a way to do the equivalent of the following MySQL limit in HQL?
14 Answers
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How to find the lowest common ancestor of two nodes in any binary tree?
...ible. For both nodes in question construct a list containing the path from root to the node by starting at the node, and front inserting the parent.
So for 8 in your example, you get (showing steps): {4}, {2, 4}, {1, 2, 4}
Do the same for your other node in question, resulting in (steps not shown...
Rails Root directory path?
How do I get my Rails app's root directory path?
9 Answers
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How can I implement a tree in Python?
... self.right = None
self.data = None
You can use it like this:
root = Tree()
root.data = "root"
root.left = Tree()
root.left.data = "left"
root.right = Tree()
root.right.data = "right"
If you need an arbitrary number of children per node, then use a list of children:
class Tree:
def...
How to switch databases in psql?
In MySQL , I used use database_name;
12 Answers
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SQL Server - inner join when updating [duplicate]
...it works with UDPATE SET FROM JOIN WHERE? Does it depend on the version of mysql?
– Farside
Apr 28 '16 at 12:45
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GUI Tool for PostgreSQL [closed]
...t to know is there any GUI Tool for PostgreSQL just like SQLYog for MySql
2 Answers
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