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How to add “on delete cascade” constraints?
... You have to drop the constraint first, then add the correct version. In standard SQL, I believe the easiest way to do this is to
start a transaction,
drop the foreign key,
add a foreign key with on delete cascade, and finally
commit the transaction
Repeat for each foreign key you want to change...
Check if table exists in SQL Server
...always best to use an INFORMATION_SCHEMA view. These views are (mostly) standard across many different databases and rarely change from version to version.
To check if a table exists use:
IF (EXISTS (SELECT *
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_SCHEMA = ...
How to SSH to a VirtualBox guest externally through a host? [closed]
... one interface already which is using NAT. Then go to the Network settings and click the Port Forwarding button. Add a new Rule. As the rule name, insert "ssh". As "Host port", insert 3022. As "Guest port", insert 22. Everything else of the rule can be left blank.
or from the command line
VBoxMan...
How to read multiple text files into a single RDD?
I want to read a bunch of text files from a hdfs location and perform mapping on it in an iteration using spark.
10 Answers...
Getting a map() to return a list in Python 3.x
I'm trying to map a list into hex, and then use the list elsewhere. In python 2.6, this was easy:
9 Answers
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How do I align views at the bottom of the screen?
...
The modern way to do this is to have a ConstraintLayout and constrain the bottom of the view to the bottom of the ConstraintLayout with app:layout_constraintBottom_toBottomOf="parent"
The example below creates a FloatingActionButton that will be aligned to the end and the bottom ...
Browserify - How to call function bundled in a file generated through browserify in browser
I am new to nodejs and browserify. I started with this link .
11 Answers
11
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How to sort strings in JavaScript
...oid exceptions. localeCompare has been supported since Internet Explorer 6 and Firefox 1. You may also see the following code used that doesn't respect a locale:
if (item1.attr < item2.attr)
return -1;
if ( item1.attr > item2.attr)
return 1;
return 0;
...
Can I call memcpy() and memmove() with “number of bytes” set to zero?
...
From the C99 standard (7.21.1/2):
Where an argument declared as size_t n specifies the length of the array for a
function, n can have the value zero on a call to that function. Unless explicitly stated
otherwise in the description o...
Python ValueError: too many values to unpack [duplicate]
...
self.materials is a dict and by default you are iterating over just the keys (which are strings).
Since self.materials has more than two keys*, they can't be unpacked into the tuple "k, m", hence the ValueError exception is raised.
In Python 2.x, t...