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How to subtract 30 days from the current datetime in mysql?
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SELECT * FROM table
WHERE exec_datetime BETWEEN DATE_SUB(NOW(), INTERVAL 30 DAY) AND NOW();
http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_date-add
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Selecting only numeric columns from a data frame
...traightforward, and robust to use on database-back-ended tibbles:
dplyr::select_if(x, is.numeric)
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Sorting dropdown alphabetically in AngularJS
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Angular has an orderBy filter that can be used like this:
<select ng-model="selected" ng-options="f.name for f in friends | orderBy:'name'"></select>
See this fiddle for an example.
It's worth noting that if track by is being used it needs to appear after the orderBy filt...
Avoid duplicates in INSERT INTO SELECT query in SQL Server
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Using NOT EXISTS:
INSERT INTO TABLE_2
(id, name)
SELECT t1.id,
t1.name
FROM TABLE_1 t1
WHERE NOT EXISTS(SELECT id
FROM TABLE_2 t2
WHERE t2.id = t1.id)
Using NOT IN:
INSERT INTO TABLE_2
(id, name)
SELECT t1.id,
t1....
How to generate an entity-relationship (ER) diagram using Oracle SQL Developer
... as follows:
Click File → Data Modeler → Import → Data Dictionary.
Select a DB connection (add one if none).
Click Next.
Check one or more schema names.
Click Next.
Check one or more objects to import.
Click Next.
Click Finish.
The ERD is displayed.
Export the diagram as follows:
Click ...
How to select bottom most rows?
I can do SELECT TOP (200) ... but why not BOTTOM (200)?
14 Answers
14
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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...
MySQL get row position in ORDER BY
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Use this:
SELECT x.id,
x.position,
x.name
FROM (SELECT t.id,
t.name,
@rownum := @rownum + 1 AS position
FROM TABLE t
JOIN (SELECT @rownum := 0) r
ORDER BY t.name)...
In MySQL, how to copy the content of one table to another table within the same database?
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INSERT INTO TARGET_TABLE SELECT * FROM SOURCE_TABLE;
EDIT: or if the tables have different structures you can also:
INSERT INTO TARGET_TABLE (`col1`,`col2`) SELECT `col1`,`col2` FROM SOURCE_TABLE;
EDIT: to constrain this..
INSERT INTO TARGET_TAB...
How do I specify new lines on Python, when writing on files?
...ly do the job. If you really want to get it right, you look up the newline character in the os package. (It's actually called linesep.)
Note: when writing to files using the Python API, do not use the os.linesep. Just use \n; Python automatically translates that to the proper newline character for ...