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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...
How to migrate/convert from SVN to Mercurial (hg) on windows
...made
much simpler: Start the TortoiseHG
Workbench from the Start menu. Select
File --> Settings. Select Extensions
from the list. Check the 'convert'
checkbox and click OK. That's it! No
need to try to generate the config
file anymore and search it in the file
system. – bgever M...
How do you convert a DataTable into a generic list?
...ataTable
//using lamdaexpression
emp = (from DataRow row in dt.Rows
select new Employee
{
_FirstName = row["FirstName"].ToString(),
_LastName = row["Last_Name"].ToString()
}).ToList();
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How do I query for all dates greater than a certain date in SQL Server?
...
select *
from dbo.March2010 A
where A.Date >= Convert(datetime, '2010-04-01' )
In your query, 2010-4-01 is treated as a mathematical expression, so in essence it read
select *
from dbo.March2010 A
where A.Date &g...
Ordering by the order of values in a SQL IN() clause
...
Use MySQL's FIELD() function:
SELECT name, description, ...
FROM ...
WHERE id IN([ids, any order])
ORDER BY FIELD(id, [ids in order])
FIELD() will return the index of the first parameter that is equal to the first parameter (other than the first paramet...
SQL: How to perform string does not equal
...
Try the following query
select * from table
where NOT (tester = 'username')
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How to highlight cell if value duplicate in same column for google spreadsheet?
...
Try this:
Select the whole column
Click Format
Click Conditional formatting
Click Add another rule (or edit the existing/default one)
Set Format cells if to: Custom formula is
Set value to: =countif(A:A,A1)>1 (or change A to your ch...
visual c++: #include files from other projects in the same solution
...n.
To access the project configuration:
Right-click on the project, and select Properties.
Select Configuration Properties->C/C++->General.
Set the path under Additional Include Directories.
How to include
To include the header file, simply write the following in your code:
#include "fi...
What's the difference between a temp table and table variable in SQL Server?
...-unique indexes too.
Table variables don't participate in transactions and SELECTs are implicitly with NOLOCK. The transaction behaviour can be very helpful, for instance if you want to ROLLBACK midway through a procedure then table variables populated during that transaction will still be populated...
Select elements by attribute in CSS
Is it possible to select elements in CSS by their HTML5 data attributes (for example, data-role )?
5 Answers
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