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How to select option in drop down using Capybara
I'm trying to select an item from a drop down menu using Capybara (2.1.0).
9 Answers
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With MySQL, how can I generate a column containing the record index in a table?
...
You may want to try the following:
SELECT l.position,
l.username,
l.score,
@curRow := @curRow + 1 AS row_number
FROM league_girl l
JOIN (SELECT @curRow := 0) r;
The JOIN (SELECT @curRow := 0) part allows the variable initiali...
Return Boolean Value on SQL Select Statement
How to return a boolean value on SQL Select Statement?
9 Answers
9
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Where can I get Google developer key
...velopers Console interface was overhauled again. For the new interface:
Select your project from the toolbar.
Open the "Gallery" using hamburger menu icon on the left side of the toolbar and select 'API Manager'.
Click 'Credentials' in the left-hand navigation.
Alternatively, you can click 'Sw...
Split column at delimiter in data frame [duplicate]
...OO=c('a|b','b|c','x|y'))
foo <- data.frame(do.call('rbind', strsplit(as.character(df$FOO),'|',fixed=TRUE)))
Or, if you want to replace the columns in the existing data.frame:
within(df, FOO<-data.frame(do.call('rbind', strsplit(as.character(FOO), '|', fixed=TRUE))))
Which produces:
ID ...
How to UPSERT (MERGE, INSERT … ON DUPLICATE UPDATE) in PostgreSQL?
...and re-try where necessary.
Some attempted solutions also fail to consider SELECT races. If you try the obvious and simple:
-- THIS IS WRONG. DO NOT COPY IT. It's an EXAMPLE.
BEGIN;
UPDATE testtable
SET somedata = 'blah'
WHERE id = 2;
-- Remember, this is WRONG. Do NOT COPY IT.
INSERT INTO testt...
Why does MYSQL higher LIMIT offset slow the query down?
...h more than 16 million records [2GB in size]. The higher LIMIT offset with SELECT, the slower the query becomes, when using ORDER BY *primary_key*
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How to get last N records with activerecord?
...e-wise - at least not up to Rails 3.1. SomeModel.last(5) will execute the select statement without a limit, returning all records of SomeModel to Ruby as an array, after which Ruby will pick out the last (5) elements. Efficiency-wise, currently, you want to use limit - particularly if you have pote...
Linq to Entities join vs groupjoin
...Join syntax would be
from p in Parent
join c in Child on p.Id equals c.Id
select new { p.Value, c.ChildValue }
returning an IEnumerable<X> where X is an anonymous type with two properties, Value and ChildValue. This query syntax uses the Join method under the hood.
GroupJoin syntax would be
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In what cases do I use malloc and/or new?
... Always use new.
If you need a big chunk of data just do something like:
char *pBuffer = new char[1024];
Be careful though this is not correct:
//This is incorrect - may delete only one element, may corrupt the heap, or worse...
delete pBuffer;
Instead you should do this when deleting an arra...
