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SQL UPDATE SET one column to be equal to a value in a related table referenced by a different column
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update q
set q.QuestionID = a.QuestionID
from QuestionTrackings q
inner join QuestionAnswers a
on q.AnswerID = a.AnswerID
where q.QuestionID is null -- and other conditions you might want
I recommend to check what the result set to update is befo...
HTML entity for the middle dot
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It's called a middle dot: ·
HTML entities:
·
·
·
In CSS:
\00B7
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Why is there no Constant feature in Java?
...hat an object is immutable when accessed through a special kind of pointer called a const-pointer When in Java, in places where I'd normally want to return a const-pointer, I instead return a reference with an interface type containing only methods that shouldn't have side effects. Unfortunately, ...
Difference between except: and except Exception as e: in Python
... print e.message, e.args
...
>>> catch()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 3, in catch
BaseException
Which a bare except does:
>>> def catch():
... try:
... raise BaseException()
... ...
selecting unique values from a column
...o if you want the whole record, the DISTINCT is worthless (unless it is an id field, and you can do a second query where id IN that list). Good news, though, if you have multiple duplicate results as a result of a JOIN you can do a GROUP BY and get the full results filtered.
– ...
mysql update column with value from another table
... UPDATE participants_registrations INNER JOIN participants ON participants.id = participants_registrations.participantId INNER JOIN registrations ON registrations.id = participants_registrations.registrationId LEFT JOIN groups ON (groups.id = registrations.groupId) SET registrations.groupId = g...
python list in sql query as parameter
....join(placeholder for unused in l)
query= 'SELECT name FROM students WHERE id IN (%s)' % placeholders
cursor.execute(query, l)
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SQL Server insert if not exists best practice
...k or so? (remember this only takes a few seconds)
– Didier Levy
Mar 14 '11 at 12:35
3
@Didier Lev...
How to set initial value and auto increment in MySQL?
How do I set the initial value for an "id" column in a MySQL table that start from 1001?
10 Answers
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Difference between left join and right join in SQL Server [duplicate]
...ed completely interchangeable. Try however Table2 left join Table1 (or its identical pair, Table1 right join Table2) to see a difference. This query should give you more rows, since Table2 contains a row with an id which is not present in Table1.
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