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How to create a unique index on a NULL column?
I am using SQL Server 2005. I want to constrain the values in a column to be unique, while allowing NULLS.
4 Answers
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How can I join multiple SQL tables using the IDs?
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BACKUP LOG cannot be performed because there is no current database backup
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Please see below image and apply changes in SqlServer :
first right click on Database --> Task --> Restore --> Select Backup File -->
Finally Apply Change in Options Tab.
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What's wrong with nullable columns in composite primary keys?
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In Sql Server a unique constraint that has a nullable column, allows the value 'null' in that column only once (given identical values for the other columns of the constraint). So such a unique constraint essentially behaves lik...
Extracting hours from a DateTime (SQL Server 2005)
...omoting lazy shorthand that leads to confusion or worse. See #6 here blogs.sqlsentry.com/aaronbertrand/… and sqlblog.com/blogs/aaron_bertrand/archive/2011/09/20/…
– Aaron Bertrand
Oct 6 '14 at 19:44
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What is the equivalent of bigint in C#?
...t am I supposed to use when handling a value in C#, which is bigint for an SQL Server database?
10 Answers
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How do I set a column value to NULL in SQL Server Management Studio?
...rtcut is specific to SSMS (and its predecessor, Enterprise Manager). Azure SQL Server features are all built in an entirely new interface on the web.
– TylerH
2 days ago
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Run PostgreSQL queries from the command line
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psql -U username -d mydatabase -c 'SELECT * FROM mytable'
If you're new to postgresql and unfamiliar with using the command line tool psql then there is some confusing behaviour you should be aware of when you've entered an i...
SQL Group By with an Order By
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In all versions of MySQL, simply alias the aggregate in the SELECT list, and order by the alias:
SELECT COUNT(id) AS theCount, `Tag` from `images-tags`
GROUP BY `Tag`
ORDER BY theCount DESC
LIMIT 20
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Difference between scaling horizontally and vertically for databases [closed]
I have come across many NoSQL databases and SQL databases. There are varying parameters to measure the strength and weaknesses of these databases and scalability is one of them. What is the difference between horizontally and vertically scaling these databases?
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