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How can I define a composite primary key in SQL?
...for the table and neither value can be NULL. If you do a query like this:
SELECT * FROM voting WHERE QuestionID = 7
it will use the primary key's index. If however you do this:
SELECT * FROM voting WHERE MemberID = 7
it won't because to use a composite index requires using all the keys from th...
Implementing Comments and Likes in database
...ucture
This pseudocode will get all the comments of photo with ID 5
SELECT * FROM actions
WHERE actions.id_Stuff = 5
AND actions.typeStuff="photo"
AND actions.typeAction = "comment"
This pseudocode will get all the likes or users who liked photo with ID 5
(you may use count() to ...
MySQL: Invalid use of group function
..., not WHERE.
The difference is: the WHERE clause filters which rows MySQL selects. Then MySQL groups the rows together and aggregates the numbers for your COUNT function.
HAVING is like WHERE, only it happens after the COUNT value has been computed, so it'll work as you expect. Rewrite your subque...
How can I calculate the number of lines changed between two commits in git?
...2>
but you can use --numstat or --shortstat as well. git log can also select commits in a variety other ways - have a look at the documentation. You might be interested in things like --since (rather than specifying commit ranges, just select commits since last week) and --no-merges (merge comm...
Similar to jQuery .closest() but traversing descendants?
...
These examples all select depth-first descendants, not breadth-first, so these can't be used to solve the original question. In my testing they all returned the first span, not the second.
– JrBaconCheez
M...
INNER JOIN vs LEFT JOIN performance in SQL Server
...(ID, Name) VALUES (4, 'Four')
INSERT #Test2 (ID, Name) VALUES (5, 'Five')
SELECT *
FROM #Test1 t1
INNER JOIN #Test2 t2
ON t2.Name = t1.Name
SELECT *
FROM #Test1 t1
LEFT JOIN #Test2 t2
ON t2.Name = t1.Name
DROP TABLE #Test1
DROP TABLE #Test2
If you run this and view the execution plan, you'll se...
Login failed for user 'DOMAIN\MACHINENAME$'
...curity >> Logins and right click on NT AUTHORITY\NETWORK SERVICE and select Properties
In newly opened screen of Login Properties, go to the “User Mapping” tab. Then, on the “User Mapping” tab, select the desired database – especially the database for which this error message is dis...
Where is the 'tests output pane'?
...
This is the correct answer. Selecting "Tests" from the combobox is the key.
– Keith
Aug 29 '14 at 14:51
...
Doctrine - How to print out the real sql, not just the prepared statement?
...hoWriteSQLWithoutParamsLogger implements SQLLogger
{
const QUERY_TYPE_SELECT="SELECT";
const QUERY_TYPE_UPDATE="UPDATE";
const QUERY_TYPE_INSERT="INSERT";
const QUERY_TYPE_DELETE="DELETE";
const QUERY_TYPE_CREATE="CREATE";
const QUERY_TYPE_ALTER="ALTER";
private $dbPlat...
How to remove Firefox's dotted outline on BUTTONS as well as links?
...
Yea it works for me too! Now how can it be done for selects ?
– 7wp
Feb 3 '10 at 19:54
16
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