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Group query results by month and year in postgresql
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select to_char(date,'Mon') as mon,
extract(year from date) as yyyy,
sum("Sales") as "Sales"
from yourtable
group by 1,2
At the request of Radu, I will explain that query:
to_char(date,'Mon') as mon, : convert...
How to trim a string in SQL Server before 2017?
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SELECT LTRIM(RTRIM(Names)) AS Names FROM Customer
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Indenting #defines
...eprocessor did not allow for space between the start of a line and the "#" character; the leading "#" had to always be placed in the first column.
Pre-ANSI C compilers are non-existent these days. Use which ever style (space before "#" or space between "#" and the identifier) you prefer.
http://ww...
How to calculate age (in years) based on Date of Birth and getDate()
...low:
try this:
DECLARE @dob datetime
SET @dob='1992-01-09 00:00:00'
SELECT DATEDIFF(hour,@dob,GETDATE())/8766.0 AS AgeYearsDecimal
,CONVERT(int,ROUND(DATEDIFF(hour,@dob,GETDATE())/8766.0,0)) AS AgeYearsIntRound
,DATEDIFF(hour,@dob,GETDATE())/8766 AS AgeYearsIntTrunc
OUTPUT:
Age...
Best way to check for “empty or null value”
... '
Demo
Empty string equals any string of spaces when cast to char(n):
SELECT ''::char(5) = ''::char(5) AS eq1
, ''::char(5) = ' '::char(5) AS eq2
, ''::char(5) = ' '::char(5) AS eq3;
Result:
eq1 | eq2 | eq3
----+-----+----
t | t | t
Test for "null or empty string" w...
PostgreSQL: Difference between text and varchar (character varying)
... article does detailed testing to show that the performance of inserts and selects for all 4 data types are similar. It also takes a detailed look at alternate ways on constraining the length when needed. Function based constraints or domains provide the advantage of instant increase of the length c...
How to find a text inside SQL Server procedures / triggers?
... find text....
DECLARE @Search varchar(255)
SET @Search='[10.10.100.50]'
SELECT DISTINCT
o.name AS Object_Name,o.type_desc
FROM sys.sql_modules m
INNER JOIN sys.objects o ON m.object_id=o.object_id
WHERE m.definition Like '%'+@Search+'%'
ORDER BY 2,1
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“Keep Me Logged In” - the best approach
...lution
A better solution would be
User is logged in and remember me is selected
Generate Token & signature and store in cookie
The tokens are random and are only valid for single autentication
The token are replace on each visit to the site
When a non-logged user visit the site the signa...
Replace a newline in TSQL
...e any of CR, LF or CR+LF. To get them all, you need something like this:
SELECT REPLACE(REPLACE(@str, CHAR(13), ''), CHAR(10), '')
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Can I change the root EBS device of my amazon EC2 instance?
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I don't have enough rep to add a comment to the selected answer, but I do want to point out that for me, /dev/sda1 did not work (did not attach as root), but using /dev/xvda worked (attached as root). The instance is one of the newer t2.micro ones using HVM.
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