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MySQL DISTINCT on a GROUP_CONCAT()
I am doing SELECT GROUP_CONCAT(categories SEPARATOR ' ') FROM table . Sample data below:
6 Answers
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JQuery: detect change in input field [duplicate]
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});
If you use the change handler, this will only fire after the user deselects the input box, which may not be what you want.
There is an example of both here: http://jsfiddle.net/6bSX6/
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Visual Studio, debug one of multiple threads
...ow (Debug -> Windows -> Threads) right-click the thread you want and select "switch to thread".
You can also choose "freeze" on the threads you don't want to debug in order to keep them from running. Don't forget to "thaw" them if you expect them to do work, however.
Further reading.
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In MySQL queries, why use join instead of where?
...FROM clause
Write the association between the tables in the WHERE clause
SELECT *
FROM TABLE_A a,
TABLE_B b
WHERE a.id = b.id
Here's the query re-written using ANSI-92 JOIN syntax:
SELECT *
FROM TABLE_A a
JOIN TABLE_B b ON b.id = a.id
From a Performance Perspective:
Where su...
What makes a SQL statement sargable?
...non-sargable is to include a field inside a function in the where clause:
SELECT ... FROM ...
WHERE Year(myDate) = 2008
The SQL optimizer can't use an index on myDate, even if one exists. It will literally have to evaluate this function for every row of the table. Much better to use:
WHERE myDat...
What is the way to quick-switch between tabs in Xcode 4
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Shortcuts are:
CMD + SHIFT + } - Select Next tab
CMD + SHIFT + { - Select Previous tab
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Return number of rows affected by UPDATE statements
...NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
DECLARE @RowCount1 INTEGER
DECLARE @RowCount2 INTEGER
DECLARE @RowCount3 INTEGER
DECLARE @RowCount4 INTEGER
UPDATE Table1 Set Column = 0 WHERE Column IS NULL
SEL...
SQL Server Profiler - How to filter trace to only display events from one database?
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Under Trace properties > Events Selection tab > select show all columns. Now under column filters, you should see the database name. Enter the database name for the Like section and you should see traces only for that database.
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mongodb: insert if not exists
...what data you want to write:
data = {"$set":{"key2":"value2"}}
Now your selected document will update the value of "key2" only and leave everything else untouched.
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Select the values of one property on all objects of an array in PowerShell
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I think you might be able to use the ExpandProperty parameter of Select-Object.
For example, to get the list of the current directory and just have the Name property displayed, one would do the following:
ls | select -Property Name
This is still returning DirectoryInfo or FileInfo obje...