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Reading Excel files from C#
...ed Properties=Excel 8.0;", fileName);
var adapter = new OleDbDataAdapter("SELECT * FROM [workSheetNameHere$]", connectionString);
var ds = new DataSet();
adapter.Fill(ds, "anyNameHere");
DataTable data = ds.Tables["anyNameHere"];
This is what I usually use. It is a little different because I u...
When should I use cross apply over inner join?
...APPLY works better on things that have no simple JOIN condition.
This one selects 3 last records from t2 for each record from t1:
SELECT t1.*, t2o.*
FROM t1
CROSS APPLY
(
SELECT TOP 3 *
FROM t2
WHERE t2.t1_id = t1.id
ORDER BY
t2.ran...
SQL-Server: Error - Exclusive access could not be obtained because the database is in use
...WITH REPLACE) in optoins tab at left hand side.
Uncheck all other options.
Select source and destination database.
Click ok.
That's it.
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Convert varchar to uniqueidentifier in SQL Server
...
DECLARE @uuid VARCHAR(50)
SET @uuid = 'a89b1acd95016ae6b9c8aabb07da2010'
SELECT CAST(
SUBSTRING(@uuid, 1, 8) + '-' + SUBSTRING(@uuid, 9, 4) + '-' + SUBSTRING(@uuid, 13, 4) + '-' +
SUBSTRING(@uuid, 17, 4) + '-' + SUBSTRING(@uuid, 21, 12)
AS UNIQUEIDENTIFIER)
...
Cannot create an array of LinkedLists in Java…?
...
IMO, this should be the selected answer. I haven't experimented, but I have the gut feeling that Sergey's #2 method creates quite a bit of overhead; and I'm POSITIVE that #1 does. A list is not as efficient as an array in several ways which I won't ...
Properly removing an Integer from a List
... is equal to Integer(1) will be removed. In both cases, the Java compiler selects the closest matching overload.
Yes, there is potential for confusion (and bugs) here, but it is a fairly uncommon use-case.
When the two List.remove methods were defined in Java 1.2, the overloads were not ambiguous...
Split value from one field to two
...);
END$$
DELIMITER ;
you would be able to build your query as follows:
SELECT SPLIT_STR(membername, ' ', 1) as memberfirst,
SPLIT_STR(membername, ' ', 2) as memberlast
FROM users;
If you prefer not to use a user defined function and you do not mind the query to be a bit more verbose, ...
MySQL/SQL: Group by date only on a Datetime column
...
Cast the datetime to a date, then GROUP BY using this syntax:
SELECT SUM(foo), DATE(mydate) FROM a_table GROUP BY DATE(a_table.mydate);
Or you can GROUP BY the alias as @orlandu63 suggested:
SELECT SUM(foo), DATE(mydate) DateOnly FROM a_table GROUP BY DateOnly;
Though I don't think...
How do I query for all dates greater than a certain date in SQL Server?
...
select *
from dbo.March2010 A
where A.Date >= Convert(datetime, '2010-04-01' )
In your query, 2010-4-01 is treated as a mathematical expression, so in essence it read
select *
from dbo.March2010 A
where A.Date &g...
How to see the CREATE VIEW code for a view in PostgreSQL?
...
select pg_get_viewdef('viewname', true)
A list of all those functions is available in the manual:
http://www.postgresql.org/docs/current/static/functions-info.html
...