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How do I create a unique ID in Java? [duplicate]
I'm looking for the best way to create a unique ID as a String in Java.
11 Answers
11
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How to drop SQL default constraint without knowing its name?
...ame
from sys.tables t
join sys.default_constraints d on d.parent_object_id = t.object_id
join sys.columns c on c.object_id = t.object_id and c.column_id = d.parent_column_id
where t.name = @table_name
and t.schema_id = schema_id(@schema_name)
and c.name = @col_name
--print @Command
execu...
Naming of ID columns in database tables
I was wondering peoples opinions on the naming of ID columns in database tables.
24 Answers
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Can I bind an array to an IN() condition?
... soulmerge is right. you'll have to construct the query-string.
<?php
$ids = array(1, 2, 3, 7, 8, 9);
$inQuery = implode(',', array_fill(0, count($ids), '?'));
$db = new PDO(...);
$stmt = $db->prepare(
'SELECT *
FROM table
WHERE id IN(' . $inQuery . ')'
);
// bindvalue is ...
Rails find_or_create_by more than one attribute?
...ibutes can be connected with an and:
GroupMember.find_or_create_by_member_id_and_group_id(4, 7)
(use find_or_initialize_by if you don't want to save the record right away)
Edit: The above method is deprecated in Rails 4. The new way to do it will be:
GroupMember.where(:member_id => 4, :group...
Does the join order matter in SQL?
... (commutativity and associativity) properties:
a LEFT JOIN b
ON b.ab_id = a.ab_id
LEFT JOIN c
ON c.ac_id = a.ac_id
is equivalent to:
a LEFT JOIN c
ON c.ac_id = a.ac_id
LEFT JOIN b
ON b.ab_id = a.ab_id
but:
a LEFT JOIN b
ON b.ab_id = a.ab_id
LEFT JOIN c
ON c....
How to select where ID in Array Rails ActiveRecord without exception
When I have array of ids, like
6 Answers
6
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In Angular, I need to search objects in an array
...gular, I have in scope a object which returns lots of objects. Each has an ID (this is stored in a flat file so no DB, and I seem to not be able to user ng-resource )
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When to add what indexes in a table in Rails
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Should I add "index" to all the foreign keys like "xxx_id"?
It would be better, because it accelerates the search in sorting in this column. And Foreign keys are something searched for a lot.
Since Version 5 of rails the index will be created automatically, for more informatio...
How can I generate a unique ID in Python? [duplicate]
I need to generate a unique ID based on a random value.
8 Answers
8
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