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UPDATE multiple tables in MySQL using LEFT JOIN
...= t1.id
SET t1.col1 = newvalue
WHERE t2.id IS NULL
Note that for a SELECT it would be more efficient to use NOT IN / NOT EXISTS syntax:
SELECT t1.*
FROM t1
WHERE t1.id NOT IN
(
SELECT id
FROM t2
)
See the article in my blog for performance details...
Replace Default Null Values Returned From Left Outer Join
... for left outer join. Is there a way to replace the default values in the select statement? I have a workaround in that I can select into a table variable but it feels a little dirty.
...
IntelliJ: Working on multiple projects
...ven Projects" window (View > Tool Windows > Maven Projects) and then select the additional pom file you want to import.
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Ruby: Easiest Way to Filter Hash Keys?
...answer: Even though this is answer (as of the time of this comment) is the selected answer, the original version of this answer is outdated.
I'm adding an update here to help others avoid getting sidetracked by this answer like I did.
As the other answer mentions, Ruby >= 2.5 added the Hash#sli...
How to integrate CSS pre-processing within Eclipse? [closed]
...and then click OK.
Find the *.scss entry in the File Associations list and select it.
After selecting *.scss, on the bottom pane Associated editors:, click the Add... button.
Make sure Internal editors is selected on the top, then find and select CSS Editor and then click OK.
This associated the f...
Default filter in Django admin
...lookup, title in self.lookup_choices:
yield {
'selected': self.value() == lookup,
'query_string': cl.get_query_string({
self.parameter_name: lookup,
}, []),
'display': title,
}
def querys...
A valid provisioning profile for this executable was not found for debug mode
...& Files" -->Target --> expand it --> right click your app and select Clean "your app"
3) Goto->Window-->Organizer
4) In the Devices tab on the left, select your iphone
5) In the Provisioning section of the selected iphone delete all the current profiles (if any)
6) Unplug your...
Querying data by joining two tables in two database on different servers
...just prefixing the database name with the other server. I.E:
-- FROM DB1
SELECT *
FROM [MyDatabaseOnDB1].[dbo].[MyTable] tab1
INNER JOIN [DB2].[MyDatabaseOnDB2].[dbo].[MyOtherTable] tab2
ON tab1.ID = tab2.ID
Once the link is established, you can also use OPENQUERY to execute a SQL st...
Replace duplicate spaces with a single space in T-SQL
...
Even tidier:
select string = replace(replace(replace(' select single spaces',' ','<>'),'><',''),'<>',' ')
Output:
select single spaces
...
PostgreSQL: Drop PostgreSQL database through command line [closed]
...rrently taking place against your database, including all idle processes.
SELECT * FROM pg_stat_activity WHERE datname='database name';
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