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SQL update fields of one table from fields of another one
...ic SQL is totally non-standard PostgreSQL syntax.
DO
$do$
BEGIN
EXECUTE (
SELECT
'UPDATE b
SET (' || string_agg( quote_ident(column_name), ',') || ')
= (' || string_agg('a.' || quote_ident(column_name), ',') || ')
FROM a
WHERE b.id = 123
AND a.id = b.id'
FROM i...
Condition within JOIN or WHERE
...of filtering criteria more easily maintainable.
For example, instead of:
SELECT *
FROM Customers c
INNER JOIN CustomerAccounts ca
ON ca.CustomerID = c.CustomerID
AND c.State = 'NY'
INNER JOIN Accounts a
ON ca.AccountID = a.AccountID
AND a.Status = 1
Write:
SELECT *
FROM Customer...
Split a collection into `n` parts with LINQ?
... group item by i++ % parts into part
select part.AsEnumerable();
return splits;
}
}
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How to avoid warning when introducing NAs by coercion
...t know how to avoid getting a warning when using as.numeric to convert a character vector.
4 Answers
...
Modifying location.hash without page scrolling
... load
if(document.location.hash){
$("#buttons li a").removeClass('selected');
s=$(document.location.hash.replace("btn_","")).addClass('selected').attr("href").replace("javascript:","");
eval(s);
}
//Click a button to change the hash
$("#buttons li a").click(function()...
Rails raw SQL example
...
You can do this:
sql = "Select * from ... your sql query here"
records_array = ActiveRecord::Base.connection.execute(sql)
records_array would then be the result of your sql query in an array which you can iterate through.
...
Open a folder using Process.Start
...er. (Thanks to @binki.)
This solution won't work for opening a folder and selecting an item, since there doesn't seem a verb for that.
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Converting file size in bytes to human-readable string
...rsion. Can you tell me, though, why you inserted the two invisible Unicode characters U+200C (ZERO WIDTH NON-JOINER) and U+200B (ZERO WIDTH SPACE) after the E oft EiB? Is this intended to be a watermark, so that you can track who used this code? If so, I think you should have made that transparent i...
Select Multiple Fields from List in Linq
...
Anonymous types allow you to select arbitrary fields into data structures that are strongly typed later on in your code:
var cats = listObject
.Select(i => new { i.category_id, i.category_name })
.Distinct()
.OrderByDescending(i => i.c...
How to do an update + join in PostgreSQL?
... coming from mysql it's unintuitive that the same join used for select won't also update just by adding a set phrase :( still - the syntax for this is probably easier for a newcomer to sql to master.
– WEBjuju
Jul 16 at 19:47
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