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How can I get around MySQL Errcode 13 with SELECT INTO OUTFILE?
I am trying to dump the contents of a table to a csv file using a MySQL SELECT INTO OUTFILE statement. If I do:
13 Answers...
Change column type from string to float in Pandas
...not (e.g. they contain non-digit strings or dates) will be left alone.
Downcasting
By default, conversion with to_numeric() will give you either a int64 or float64 dtype (or whatever integer width is native to your platform).
That's usually what you want, but what if you wanted to save some memory a...
How to drop SQL default constraint without knowing its name?
...MySchema'
set @table_name = N'Department'
set @col_name = N'ModifiedDate'
select @Command = 'ALTER TABLE ' + @schema_name + '.[' + @table_name + '] DROP CONSTRAINT ' + d.name
from sys.tables t
join sys.default_constraints d on d.parent_object_id = t.object_id
join sys.columns c on c.object_id ...
Is there a Max function in SQL Server that takes two values like Math.Max in .NET?
...
return isnull(@val2,@val1)
end
... and you would call it like so ...
SELECT o.OrderId, dbo.InlineMax(o.NegotiatedPrice, o.SuggestedPrice)
FROM Order o
share
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How can I get column names from a table in SQL Server?
... much more by querying the Information Schema views.
This sample query:
SELECT *
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_NAME = N'Customers'
Can be made over all these DB objects:
CHECK_CONSTRAINTS
COLUMN_DOMAIN_USAGE
COLUMN_PRIVILEGES
COLUMNS
CONSTRAINT_COLUMN_USAGE
CONSTRAINT_...
How can I remove duplicate rows?
...
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...
When to use symbols instead of strings in Ruby?
...Printing the symbols will be slower than printing strings because they are cast to strings.
Having lots of different symbols will increase the overall memory usage of your application since they are never deallocated. And you are never using all strings from your code at the same time.
Use case b...
jQuery - selecting elements from inside a element
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Actually, $('#id', this); would select #id at any descendant level, not just the immediate child. Try this instead:
$(this).children('#id');
or
$("#foo > #moo")
or
$("#foo > span")
...
form serialize javascript (no framework)
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Here is pure JavaScript approach:
var form = document.querySelector('form');
var data = new FormData(form);
var req = new XMLHttpRequest();
req.send(data);
Though it seems to be working only for POST requests.
https://developer.mozilla.org/en-US/docs/Web/API/FormData
...
Disable Drag and Drop on HTML elements?
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This might work: You can disable selecting with css3 for text, image and basically everything.
.unselectable {
-moz-user-select: -moz-none;
-khtml-user-select: none;
-webkit-user-select: none;
/*
Introduced in IE 10.
See http://ie.mic...