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What are the Ruby Gotchas a newbie should be warned about? [closed]
...as constants, so local variables should begin with a lowercase letter.
The characters $ and @ do not indicate variable data type as in Perl, but rather function as scope resolution operators.
To denote floating point numbers, one must follow with a zero digit (99.0) or an explicit conversion (99.to_...
What character to use to put an item at the end of an alphabetic list?
... _ ' to the item I want in first position.
Is there some sort of magical character I could use to put an item at the end of the list?
...
Is it possible to GROUP BY multiple columns using MySQL?
Is it possible to GROUP BY more than one column in a MySQL SELECT query? For example:
7 Answers
...
How to remove a column from an existing table?
...lete a column from an unexisting table ;-)
BEGIN TRANSACTION
IF exists (SELECT * FROM sys.columns c
INNER JOIN sys.objects t ON (c.[object_id] = t.[object_id])
WHERE t.[object_id] = OBJECT_ID(N'[dbo].[MyTable]')
AND c.[name] = 'ColumnName')
BEGIN TRY
ALTER TABLE [dbo].[MyTable] DRO...
PostgreSQL delete with inner join
...ctprice
WHERE m_pricelist_version_id='1000020' AND
m_product_id IN (SELECT m_product_id
FROM m_product
WHERE upc = '7094');
share
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improve t...
Create a date from day month and year with T-SQL
...are @Year Integer Set @Year = 2006
-- ------------------------------------
Select DateAdd(day, @DayOfMonth - 1,
DateAdd(month, @Month - 1,
DateAdd(Year, @Year-1900, 0)))
It works as well, has added benefit of not doing any string conversions, so it's pure arithmetic proce...
Fastest way to check if a string is JSON in PHP?
...
Checking first character of string for {, [ or first symbol of any other literal can potentially greatly speed this one up when many of incoming strings are expected to be non-JSON.
– Oleg V. Volkov
Se...
Oracle: how to UPSERT (update or insert into a table?)
...e mergetest(a number, b number);
call ups(10);
call ups(10);
call ups(20);
select * from mergetest;
A B
---------------------- ----------------------
10 2
20 1
s...
Select second last element with css
I already know of :last-child. But is there a way to select the div:
2 Answers
2
...
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...