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What does SQL clause “GROUP BY 1” mean?
...
SELECT account_id, open_emp_id
^^^^ ^^^^
1 2
FROM account
GROUP BY 1;
In above query GROUP BY 1 refers to the first column in select statement which is
account_id.
You also can speci...
how to emulate “insert ignore” and “on duplicate key update” (sql merge) with postgresql?
... two queries, one for INSERT and one for UPDATE (as an appropriate join/subselect of course - no need to write your main filter twice)
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T-SQL: Selecting rows to delete via joins
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DELETE FROM TableA a WHERE [filter condition on TableA]
AND (a.BId IN (SELECT a.BId FROM TableB b JOIN TableA a
ON a.BId = b.BId
WHERE [filter condition on TableB]))
(Note Interbase doesn't support the AS keyword for aliases)
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foreach with index [duplicate]
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You can do the following
foreach (var it in someCollection.Select((x, i) => new { Value = x, Index = i }) )
{
if (it.Index > SomeNumber) //
}
This will create an anonymous type value for every entry in the collection. It will have two properties
Value: with the ori...
Find nearest latitude/longitude with an SQL query
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SELECT latitude, longitude, SQRT(
POW(69.1 * (latitude - [startlat]), 2) +
POW(69.1 * ([startlng] - longitude) * COS(latitude / 57.3), 2)) AS distance
FROM TableName HAVING distance < 25 ORDER BY distance;
where ...
How to get ERD diagram for an existing database?
...t that up in Manage, in which case all your databases will be available to select in step 3)
Import all objects (it will warn that you are importing to the current model, which is fine since it is empty).
Now switch back to the Design tab to see your ERD.
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What is the difference between a stored procedure and a view?
...iece of SQL, I would define a view like:
CREATE VIEW vw_user_profile
AS
SELECT A.user_id, B.profile_description
FROM tbl_user A LEFT JOIN tbl_profile B ON A.user_id = b.user_id
GO
Thus, if I want to query profile_description by user_id in the future, all I have to do is:
SELECT profile_descr...
Best way to do nested case statement logic in SQL Server
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You could try some sort of COALESCE trick, eg:
SELECT COALESCE(
CASE WHEN condition1 THEN calculation1 ELSE NULL END,
CASE WHEN condition2 THEN calculation2 ELSE NULL END,
etc...
)
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Difference between “change” and “input” event for an `input` element
...an element is changed through the user interface.
onchange occurs when the selection, the checked state or the contents of an element have changed. In some cases, it only occurs when the element loses the focus or when pressing return (Enter) and the value has been changed. The onchange attribute ca...
Delete duplicate rows from small table
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DELETE FROM dupes a
WHERE a.ctid <> (SELECT min(b.ctid)
FROM dupes b
WHERE a.key = b.key);
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