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Finding median of list in Python
...t though: sorting is much more work in the worst case (Theta(n lg n)) than selecting the median (Theta(n))...
– Jeremy
Jun 11 '19 at 13:33
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| ...
MySQL string replace
...
Yes, MySQL has a REPLACE() function:
mysql> SELECT REPLACE('www.mysql.com', 'w', 'Ww');
-> 'WwWwWw.mysql.com'
http://dev.mysql.com/doc/refman/5.0/en/string-functions.html#function_replace
Note that it's easier if you make that an alias when using SELECT
SEL...
SQLAlchemy IN clause
...3,456))).all()
edit: Without the ORM, it would be
session.execute(
select(
[MyUserTable.c.id, MyUserTable.c.name],
MyUserTable.c.id.in_((123, 456))
)
).fetchall()
select() takes two parameters, the first one is a list of fields to retrieve, the second one is the where ...
How do I kill all the processes in Mysql “show processlist”?
...peration saves time. Do it in MySql itself:
Run these commands
mysql> select concat('KILL ',id,';') from information_schema.processlist
where user='root' and time > 200 into outfile '/tmp/a.txt';
mysql> source /tmp/a.txt;
Reference
---------edit------------
if you do not want to sto...
How to select following sibling/xml tag using xpath
... we are interested in. In this case you can omit ./ . Also, if you want to select the immediate following sibling, use: following-sibling::td[1], otherwise, if there are more than one following siblings, all will be selected.
– Dimitre Novatchev
Jan 23 '16 at 2...
How to sort with a lambda?
...nswer you're looking for? Browse other questions tagged c++ sorting lambda char constants or ask your own question.
Is it possible to insert multiple rows at a time in an SQLite database?
...
This can be recast into SQLite as:
INSERT INTO 'tablename'
SELECT 'data1' AS 'column1', 'data2' AS 'column2'
UNION ALL SELECT 'data1', 'data2'
UNION ALL SELECT 'data1', 'data2'
UNION ALL SELECT 'data1', 'data2'
a note on performance
I originally used this technique to efficiently lo...
Replace all non-alphanumeric characters in a string
I have a string with which i want to replace any character that isn't a standard character or number such as (a-z or 0-9) with an asterisk. For example, "h^&ell`.,|o w]{+orld" is replaced with "h*ell*o*w*orld". Note that multiple characters such as "^&" get replaced with one asterisk. How would I go...
Is SQL syntax case sensitive?
...
The SQL Keywords are case-insensitive (SELECT, FROM, WHERE, etc), but are often written in all caps. However in some setups table and column names are case-sensitive. MySQL has a configuration option to enable/disable it. Usually case-sensitive table and column na...
ORA-00054: resource busy and acquire with NOWAIT specified or timeout expired
...table is already locked by some query. For example, you may have executed "select for update" and have not yet committed/rollbacked and fired another select query. Do a commit/rollback before executing your query.
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