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How can I do an UPDATE statement with JOIN in SQL Server?
...to do it in ANSI/ISO (aka should work on any SQL DBMS), MySQL, SQL Server, and Oracle. Be advised that my suggested ANSI/ISO method will typically be much slower than the other two methods, but if you're using a SQL DBMS other than MySQL, SQL Server, or Oracle, then it may be the only way to go (e.g...
Joining three tables using MySQL
...t", c.name "Course"
from student s, bridge b, course c
where b.sid = s.sid and b.cid = c.cid
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C# getting the path of %AppData%
...ent.GetFolderPath(Environment.SpecialFolder.ApplicationData) returns empty string for me (IIS 7, VS 2011). Problem solved using Simon_Weaver solution - mapping using MapPath.
– Mike Keskinov
May 21 '12 at 19:16
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Does java have a int.tryparse that doesn't throw an exception for bad data? [duplicate]
C# has Int.TryParse: Int32.TryParse Method (String, Int32%)
3 Answers
3
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How to construct a set out of list items in python?
...
If you have a list of hashable objects (filenames would probably be strings, so they should count):
lst = ['foo.py', 'bar.py', 'baz.py', 'qux.py', Ellipsis]
you can construct the set directly:
s = set(lst)
In fact, set will work this way with any iterable object! (Isn't duck typing gre...
Why use the 'ref' keyword when passing an object?
... useful too if you want to change the value of an immutable object, e.g. a string. You cannot change the value of a string once it has been created. But by using a ref, you could create a function that changes the string for another one that has a different value.
It is not a good idea to use ref un...
How do I drop a foreign key constraint only if it exists in sql server?
...gn_keys
WHERE object_id = OBJECT_ID(N'dbo.FK_TableName_TableName2')
AND parent_object_id = OBJECT_ID(N'dbo.TableName')
)
ALTER TABLE [dbo.TableName] DROP CONSTRAINT [FK_TableName_TableName2]
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Rails: Why does find(id) raise an exception in rails? [duplicate]
...ctiveRecord, the default behaviour is to return nil or false for failures, and leave the exception control flow to methods ending in a bang (#save!).
– Marten Veldthuis
Aug 12 '11 at 8:07
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How do I select an entire row which has the largest ID in the table?
...nique. I did some benchmarking using set profiling = 1; ...; show profiles and it appears our solutions have the same performance using MySQL. For my own knowledge, do you know what DBMS has poorer performance for subselects?
– unutbu
Feb 7 '14 at 20:08
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SQL “select where not in subquery” returns no results
...emantically the same.
When it is nullable, NOT IN is different, since IN (and, therefore, NOT IN) return NULL when a value does not match anything in a list containing a NULL.
This may be confusing but may become more obvious if we recall the alternate syntax for this:
common_id = ANY
(
SELECT c...