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How do I (or can I) SELECT DISTINCT on multiple columns?
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SELECT DISTINCT a,b,c FROM t
is roughly equivalent to:
SELECT a,b,c FROM t GROUP BY a,b,c
It's a good idea to get used to the GROUP BY syntax, as it's more powerful.
For your query, I'd do it like this:
UPDATE sale...
Programmatically selecting text in an input field on iOS devices (mobile Safari)
How do you programmatically select the text of an input field on iOS devices, e.g. iPhone, iPad running mobile Safari?
10 A...
Extract date (yyyy/mm/dd) from a timestamp in PostgreSQL
... to a date by suffixing it with ::date. Here, in psql, is a timestamp:
# select '2010-01-01 12:00:00'::timestamp;
timestamp
---------------------
2010-01-01 12:00:00
Now we'll cast it to a date:
wconrad=# select '2010-01-01 12:00:00'::timestamp::date;
date
------------
201...
MySQL order by before group by
... table on both the post_author and the max date.
The solution should be:
SELECT p1.*
FROM wp_posts p1
INNER JOIN
(
SELECT max(post_date) MaxPostDate, post_author
FROM wp_posts
WHERE post_status='publish'
AND post_type='post'
GROUP BY post_author
) p2
ON p1.post_author = p...
How to take MySQL database backup using MySQL Workbench?
...ble) within Server Administration.
Steps to Create New Server Instance:
Select New Server Instance option within Server Administrator.
Provide connection details.
After creating new server instance , it will be available in Server Administration list. Double click on Server instance you have cr...
Select columns from result set of stored procedure
...stored procedure that returns 80 columns, and 300 rows. I want to write a select that gets 2 of those columns. Something like
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Counting DISTINCT over multiple columns
... function turns the ints into varchars to make the distinct more reliable
SELECT COUNT(DISTINCT (CHECKSUM(DocumentId,DocumentSessionId)) + CHECKSUM(REVERSE(DocumentId),REVERSE(DocumentSessionId)) )
FROM DocumentOutPutItems
...
MySQL “Group By” and “Order By”
I want to be able to select a bunch of rows from a table of e-mails and group them by the from sender. My query looks like this:
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Search of table names
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I'm using this and works fine
SELECT * FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_NAME LIKE '%%'
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Using column alias in WHERE clause of MySQL query produces an error
... though, by putting the expression directly into the WHERE x IN y clause:
SELECT `users`.`first_name`,`users`.`last_name`,`users`.`email`,SUBSTRING(`locations`.`raw`,-6,4) AS `guaranteed_postcode`
FROM `users` LEFT OUTER JOIN `locations`
ON `users`.`id` = `locations`.`user_id`
WHERE SUBSTRING(`loca...