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difference between primary key and unique key
...ey, unique key, etc are collectively called as Candidate Key.
However, DBA selected a key from candidate key for searching records is called Primary key.
Difference between Primary Key and Unique key
1. Behavior: Primary Key is used to identify a row (record) in a table, whereas Unique-key is to...
SQL Server Management Studio won't let me add an index to a table
...l I had to do was close the Table Designer and right-click on the Index to select "Properties" in order to add/edit them.... All these years wasted on writing custom scripts. face-palm I want my youth back!
– MikeTeeVee
Nov 17 '15 at 19:55
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GROUP_CONCAT ORDER BY
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You can use ORDER BY inside the GROUP_CONCAT function in this way:
SELECT li.client_id, group_concat(li.percentage ORDER BY li.views ASC) AS views,
group_concat(li.percentage ORDER BY li.percentage ASC)
FROM li GROUP BY client_id
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How to execute XPath one-liners from shell?
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You should try these tools :
xmlstarlet : can edit, select, transform... Not installed by default, xpath1
xmllint : often installed by default with libxml2-utils, xpath1 (check my wrapper to have --xpath switch on very old releases and newlines delimited output (v < 2.9.9)
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Where does mongodb stand in the CAP theorem?
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MongoDB selects Consistency over Availability whenever there is a Partition. What it means is that when there's a partition(P) it chooses Consistency(C) over Availability(A).
To understand this, Let's understand how MongoDB does rep...
Access Denied for User 'root'@'localhost' (using password: YES) - No Privileges?
...th socket, which means you just connect with sudo mysql. If you run sql :
SELECT user,authentication_string,plugin,host FROM mysql.user;
then you will see it :
+------------------+-------------------------------------------+-----------------------+-----------+
| user | authentication...
Focusable EditText inside ListView
... . All I want to do is be able to use the jogball/arrows, to navigate the selector to individual items like normal, but when I get to a particular row -- even if I have to explicitly identify the row -- that has a focusable child, I want that child to take focus instead of indicating the position w...
What Xcode keyboard shortcuts do you use regularly? [closed]
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Uncommenting only does not work when your selection contains one or more lines that are not already commented.
– DarkByte
Jun 19 '14 at 8:03
a...
PostgreSQL delete with inner join
...ctprice
WHERE m_pricelist_version_id='1000020' AND
m_product_id IN (SELECT m_product_id
FROM m_product
WHERE upc = '7094');
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git stash apply version
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git stash list
then select the stash to apply and use only number:
git stash apply 1
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