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How to get number of rows using SqlDataReader in C#
...reading all rows (and then you might as well store them)
run a specialized SELECT COUNT(*) query beforehand.
Going twice through the DataReader loop is really expensive, you would have to re-execute the query.
And (thanks to Pete OHanlon) the second option is only concurrency-safe when you use a ...
How to get Last record from Sqlite?
...
Try this:
SELECT *
FROM TABLE
WHERE ID = (SELECT MAX(ID) FROM TABLE);
OR
you can also used following solution:
SELECT * FROM tablename ORDER BY column DESC LIMIT 1;
...
How can I find non-ASCII characters in MySQL?
...ng as "ASCII", but I would suggest trying a variant of a query like this:
SELECT * FROM tableName WHERE columnToCheck NOT REGEXP '[A-Za-z0-9]';
That query will return all rows where columnToCheck contains any non-alphanumeric characters. If you have other characters that are acceptable, add them ...
jQuery to serialize only elements within a div
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Wouldn't $("#divId").find("select, textarea, input").serialize(); yeild better performance? I imagine the above could get slow if the div had lots of elements, like a table with several rows/columns.
– David Murdoch
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What is causing this ActiveRecord::ReadOnlyRecord error?
...s automatically inferred only if :joins was specified without an explicit :select nor an explicit (or finder-scope-inherited) :readonly option (see the implementation of set_readonly_option! in active_record/base.rb for Rails 2.3.4, or the implementation of to_a in active_record/relation.rb and of c...
“Unresolved inclusion” error with Eclipse CDT for C standard library headers
...lipse, you open the Properties of your project, expand "C/C++ General" and select "Paths and Symbols".
Make sure you have added the include dir for each language you are using. (In my case, I needed to just add it to GNU C++.)
...
Multiple file upload in php
... what would the expected outcome be? Browser allowing multiple files to be selected?
– Sven
Oct 3 '12 at 17:41
9
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How can I remove duplicate rows?
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Assuming no nulls, you GROUP BY the unique columns, and SELECT the MIN (or MAX) RowId as the row to keep. Then, just delete everything that didn't have a row id:
DELETE FROM MyTable
LEFT OUTER JOIN (
SELECT MIN(RowId) as RowId, Col1, Col2, Col3
FROM MyTable
GROUP BY Co...
What does the “+” (plus sign) CSS selector mean?
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See adjacent selectors on W3.org.
In this case, the selector means that the style applies only to paragraphs directly following another paragraph.
A plain p selector would apply the style to every paragraph in the page.
This will onl...
SQL WHERE ID IN (id1, id2, …, idn)
... But how would you pass the list of ids that you need? (Seeing you can't select a range or something like that).
– raam86
Oct 18 '16 at 14:32
1
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