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How to create a MySQL hierarchical recursive query
... or self-joins.
MySQL 8+
with recursive cte (id, name, parent_id) as (
select id,
name,
parent_id
from products
where parent_id = 19
union all
select p.id,
p.name,
p.parent_id
from products p
inner join cte
...
SSH to Elastic Beanstalk instance
... region.
Configure Security Group
In the AWS console, open the EC2 tab.
Select the relevant region and click on Security Group.
You should have an elasticbeanstalk-default security group if you have launched an Elastic Beanstalk instance in that region.
Edit the security group to add a rule for S...
Delete duplicate records in SQL Server?
...r the dupes by empId, and delete all but the first one.
delete x from (
select *, rn=row_number() over (partition by EmployeeName order by empId)
from Employee
) x
where rn > 1;
Run it as a select to see what would be deleted:
select *
from (
select *, rn=row_number() over (partition b...
MySQL Conditional Insert
...
If your DBMS does not impose limitations on which table you select from when you execute an insert, try:
INSERT INTO x_table(instance, user, item)
SELECT 919191, 123, 456
FROM dual
WHERE NOT EXISTS (SELECT * FROM x_table
WHERE user = ...
Is there an onSelect event or equivalent for HTML ?
I have an input form that lets me select from multiple options, and do something when the user changes the selection. Eg,
...
How to randomly select an item from a list?
...ults, but depending on the start seed, it's not guaranteed. If you want to select n distinct random elements from a list lst, use random.sample(lst, n)
– Graham
Dec 23 '18 at 17:02
...
SQL query to select dates between two dates
...
you should put those two dates between single quotes like..
select Date, TotalAllowance from Calculation where EmployeeId = 1
and Date between '2011/02/25' and '2011/02/27'
or can use
select Date, TotalAllowance from Calculation where EmployeeId = 1
and Da...
jQuery to retrieve and set selected option value of html select element
I am attempting to retrieve and set the selected value of a select element (drop down list) with jQuery.
9 Answers
...
How do I make a placeholder for a 'select' box?
...s which is working out just fine. But I'd like to use a placeholder for my selectboxes as well. Of course I can just use this code:
...
How do I query if a database schema exists
...
Are you looking for sys.schemas?
IF NOT EXISTS (SELECT * FROM sys.schemas WHERE name = 'jim')
BEGIN
EXEC('CREATE SCHEMA jim')
END
Note that the CREATE SCHEMA must be run in its own batch (per the answer below)
...