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When and why I should use session_regenerate_id()?
Why and when should I use the session_regenerate_id() function in php?
Should I always use it after I use the session_start() ?
I've read that I have to use it to prevent session fixation, is this the only reason?
...
How do I find a “gap” in running counter with SQL?
...
In MySQL and PostgreSQL:
SELECT id + 1
FROM mytable mo
WHERE NOT EXISTS
(
SELECT NULL
FROM mytable mi
WHERE mi.id = mo.id + 1
)
ORDER BY
id
LIMIT 1
In SQL Server:
SELECT TOP 1
id + 1
FR...
PostgreSQL DISTINCT ON with different ORDER BY
...expression(s).
Official documentation
So you'll have to add the address_id to the order by.
Alternatively, if you're looking for the full row that contains the most recent purchased product for each address_id and that result sorted by purchased_at then you're trying to solve a greatest N per gr...
Left Join With Where Clause
...FT JOIN
`character_settings`
ON `character_settings`.`setting_id` = `settings`.`id`
AND `character_settings`.`character_id` = '1'
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Many-to-many relationship with the same model in rails?
...the schema for that:
create_table "post_connections", :force => true, :id => false do |t|
t.integer "post_a_id", :null => false
t.integer "post_b_id", :null => false
end
By default, Rails will call this table a combination of the names of the two tables we're joining. But that wou...
Can table columns with a Foreign Key be NULL?
I have a table which has several ID columns to other tables.
7 Answers
7
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SQL Server: Filter output of sp_who2
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You could try something like
DECLARE @Table TABLE(
SPID INT,
Status VARCHAR(MAX),
LOGIN VARCHAR(MAX),
HostName VARCHAR(MAX),
BlkBy VARCHAR(MAX),
DBName VARCHAR(MAX),
Command VARCHAR(MAX),
CPUTime INT,
DiskIO INT,
...
Check if object value exists within a Javascript array of objects and if not add a new object to arr
...
I've assumed that ids are meant to be unique here. some is a great function for checking the existence of things in arrays:
const arr = [{ id: 1, username: 'fred' }, { id: 2, username: 'bill' }, { id: 3, username: 'ted' }];
function ad...
How do SQL EXISTS statements work?
...ists' a row in the Order table that meets the condition Suppliers.supplier_id (this comes from Outer query current 'row') = Orders.supplier_id. When you find the first matching row, stop right there - the WHERE EXISTS has been satisfied.
The magic link between the outer query and the subquery lies...
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...