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SQL - using alias in Group By
... following order:
FROM clause
WHERE clause
GROUP BY clause
HAVING clause
SELECT clause
ORDER BY clause
For most relational database systems, this order explains which names (columns or aliases) are valid because they must have been introduced in a previous step.
So in Oracle and SQL Server, you...
SQL Query to concatenate column values from multiple rows in Oracle
...on on string aggregation techniques. A very common one is to use LISTAGG:
SELECT pid, LISTAGG(Desc, ' ') WITHIN GROUP (ORDER BY seq) AS description
FROM B GROUP BY pid;
Then join to A to pick out the pids you want.
Note: Out of the box, LISTAGG only works correctly with VARCHAR2 columns.
...
How to submit form on change of dropdown list?
I am creating a page in JSP where I have a dropdown list and once the user selects a value he has to click on the go button and then the value is sent to the Servlet.
...
Get bitcoin historical data [closed]
I want to do my own bitcoin chart.
7 Answers
7
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MySQL - Rows to Columns
...ms that I'll use for the rest of this post. This will be the base table:
select * from history;
+--------+----------+-----------+
| hostid | itemname | itemvalue |
+--------+----------+-----------+
| 1 | A | 10 |
| 1 | B | 3 |
| 2 | A | 9...
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...
What's the point of 'const' in the Haskell Prelude?
..., no matter the second, you can do:
listOfNothings :: String -> [Maybe Char]
listOfNothings = (map . const) Nothing
or, more explicitly:
listOfNothing st = map (const Nothing) st
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Get the index of the nth occurrence of a string?
...
Note: I have added Regex.Escape to original solution to allow searching characters which have special meaning to regex engine.
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How to Join to first row
...
SELECT Orders.OrderNumber, LineItems.Quantity, LineItems.Description
FROM Orders
JOIN LineItems
ON LineItems.LineItemGUID =
(
SELECT TOP 1 LineItemGUID
FROM LineItems
W...
Select data from date range between two dates
...uch more simple (only two cases against four).
Your SQL will look like:
SELECT * FROM Product_sales
WHERE NOT (From_date > @RangeTill OR To_date < @RangeFrom)
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