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Hibernate show real SQL [duplicate]
...ent to your database.
this_ is an alias for that instance of the employee table.
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How to express a NOT IN query with ActiveRecord/Rails?
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Using Arel:
topics=Topic.arel_table
Topic.where(topics[:forum_id].not_in(@forum_ids))
or, if preferred:
topics=Topic.arel_table
Topic.where(topics[:forum_id].in(@forum_ids).not)
and since rails 4 on:
topics=Topic.arel_table
Topic.where.not(topics[:f...
How to select the rows with maximum values in each group with dplyr? [duplicate]
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For me, it helped to count the number of values per group. Copy the count table into a new object. Then filter for the max of the group based on the first grouping characteristic. For example:
count_table <- df %>%
group_by(A, B) %>%
count() %>%
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What characters are allowed in an email address?
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I've tried to implement this in postfix via pcre access table under a check_recipient_access restriction, first turning the 3 long pcres (from the linked page) into one line each and topping and tailing thus: /^[...pcre..]$/ DUNNO, then adding a final line /.*/ REJECT, but it stil...
Execute Insert command and return inserted Id in Sql
I am inserting some values into a SQL table using C# in MVC 4. Actually, I want to insert values and return the 'ID' of last inserted record. I use the following code.
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How to check if a function exists on a SQL database
...s for this type argument, particularly:
FN : Scalar function
IF : Inline table-valued function
TF : Table-valued-function
FS : Assembly (CLR) scalar-function
FT : Assembly (CLR) table-valued function
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A std::map that keep track of the order of insertion?
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You might combine a std::vector with a std::tr1::unordered_map (a hash table). Here's a link to Boost's documentation for unordered_map. You can use the vector to keep track of the insertion order and the hash table to do the frequent lookups. If you're doing hundreds of thousands of lookups,...
How to include “zero” / “0” results in COUNT aggregate?
...u want an outer join for this (and you need to use person as the "driving" table)
SELECT person.person_id, COUNT(appointment.person_id) AS "number_of_appointments"
FROM person
LEFT JOIN appointment ON person.person_id = appointment.person_id
GROUP BY person.person_id;
The reason why this is wo...
Why are C# interface methods not declared abstract or virtual?
...phic with regards to the interface type, so it needs a slot on the virtual table to allow virtual method dispatching.
– Jordão
Sep 1 '10 at 20:06
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How to get the top 10 values in postgresql?
... *,
rank() over (order by some_value_column desc) as my_rank
from mytable) subquery
where my_rank <= 10
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