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How to return result of a SELECT inside a function in PostgreSQL?
...ERY:
CREATE OR REPLACE FUNCTION word_frequency(_max_tokens int)
RETURNS TABLE (txt text -- also visible as OUT parameter inside function
, cnt bigint
, ratio bigint) AS
$func$
BEGIN
RETURN QUERY
SELECT t.txt
, count(*) AS cnt -- co...
PostgreSQL - max number of parameters in “IN” clause?
... possible if the inputs are all scalars (no RowExprs) and there is a
* suitable array type available. If not, we fall back to a boolean
* condition tree with multiple copies of the lefthand expression.
* Also, any IN-list items that contain Vars are handled as separate
* boolean conditions, bec...
How do I specify unique constraint for multiple columns in MySQL?
I have a table:
14 Answers
14
...
Remove columns from dataframe where ALL values are NA
... function to reduce the size. The answer bellow using Filter or using data.table will help your memory usage.
– mtelesha
Dec 9 '15 at 15:21
3
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Entity Framework: One Database, Multiple DbContexts. Is this a bad idea? [closed]
...ngle context per app can be expensive if the application has many entities/tables. Thus depending on the schema, it might also make sense to have multiple contexts.
– DarthVader
May 13 '13 at 7:04
...
What is NSLayoutConstraint “UIView-Encapsulated-Layout-Height” and how should I go about forcing it
I have a UITableView running under iOS 8 and I'm using automatic cell heights from constraints in a storyboard.
17 Answer...
select * vs select column
...
It always pulls a tuple (except in cases where the table has been vertically segmented - broken up into columns pieces), so, to answer the question you asked, it doesn't matter from a performance perspective. However, for many other reasons, (below) you should always select ...
What is the best way to use a HashMap in C++?
...rdered map insert and access is in O(1). It is just another name for a hashtable.
An example with (ordered) std::map:
#include <map>
#include <iostream>
#include <cassert>
int main(int argc, char **argv)
{
std::map<std::string, int> m;
m["hello"] = 23;
// check if ke...
What is the difference between bottom-up and top-down?
...ds the root.
Tabulation - You can also think of dynamic programming as a "table-filling" algorithm (though usually multidimensional, this 'table' may have non-Euclidean geometry in very rare cases*). This is like memoization but more active, and involves one additional step: You must pick, ahead of...
What's the difference between @JoinColumn and mappedBy when using a JPA @OneToMany association
...t this entity is the owner of the relationship (that is: the corresponding table has a column with a foreign key to the referenced table), whereas the attribute mappedBy indicates that the entity in this side is the inverse of the relationship, and the owner resides in the "other" entity. This also ...