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Finding duplicate values in a SQL table
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SELECT
name, email, COUNT(*)
FROM
users
GROUP BY
name, email
HAVING
COUNT(*) > 1
Simply group on both of the columns.
Note: the older ANSI standard is to have all non-aggregated columns in the GROUP BY ...
SQL Server: SELECT only the rows with MAX(DATE)
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If rownumber() over(...) is available for you ....
select OrderNO,
PartCode,
Quantity
from (select OrderNO,
PartCode,
Quantity,
row_number() over(partition by OrderNO order by DateEntered desc) as rn
from YourTable) a...
Can we have multiple “WITH AS” in single sql - Oracle SQL
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You can do this as:
WITH abc AS( select
FROM ...)
, XYZ AS(select
From abc ....) /*This one uses "abc" multiple times*/
Select
From XYZ.... /*using abc, XYZ multiple times*/
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How to restore to a different database in sql server?
...restore. Kill all running processes by right clicking on each process and selecting "kill process".
Right click on the database you wish to restore, and select Tasks-->Restore-->From Database.
Select the "From Device:" radio button.
Select ... and choose the backup file of the other database ...
SELECT INTO Variable in MySQL DECLARE causes syntax error?
I´d like to SELECT a single value into a variable. I´d tried to following:
11 Answers
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MySQL Query to select data from last week?
Hi I have a table with a date field and some other information.
I want to select all entries from the past week, (week start from Sunday).
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How do you connect to multiple MySQL databases on a single webpage?
...d);
$dbh2 = mysql_connect($hostname, $username, $password, true);
mysql_select_db('database1', $dbh1);
mysql_select_db('database2', $dbh2);
Then to query database 1 pass the first link identifier:
mysql_query('select * from tablename', $dbh1);
and for database 2 pass the second:
mysql_query...
How to reset postgres' primary key sequence when it falls out of sync?
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-- Login to psql and run the following
-- What is the result?
SELECT MAX(id) FROM your_table;
-- Then run...
-- This should be higher than the last result.
SELECT nextval('your_table_id_seq');
-- If it's not higher... run this set the sequence last to your highest id.
-- (wise to run...
Get the value of a dropdown in jQuery
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$('#Crd').val() will give you the selected value of the drop down element. Use this to get the selected options text.
$('#Crd option:selected').text();
share
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Run PostgreSQL queries from the command line
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psql -U username -d mydatabase -c 'SELECT * FROM mytable'
If you're new to postgresql and unfamiliar with using the command line tool psql then there is some confusing behaviour you should be aware of when you've entered an interactive session.
For example, ...