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mysql_info [2010-12-10 10:33]
Joakim Forsgren 		mysql_info [2022-07-18 13:20]
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-====== Mysql info ====== 
-Gick igen några SQL-frågor 
-<code> 
-SELECT *,COUNT(ItemID) as Number FROM Threads LEFT JOIN Items USING(ThreadID) GROUP BY (ThreadID) 
  
-SELECT lab5_Threads.*,lab5_Users.*,COUNT(ItemID) as NumItems FROM `lab5_Threads` INNER JOIN `lab5_Users` USING(UserID) LEFT JOIN `lab5_Items` USING(ThreadID) GROUP BY ThreadID 
- 
- 
-# För att ta bort, gör först en korrekt select 
-SELECT * FROM `lab5_Threads` RIGHT JOIN lab5_Items USING(ThreadID) WHERE Thread IS NULL 
-# sen ändrar man den till en delete 
-DELETE lab5_Items FROM `lab5_Threads` RIGHT JOIN lab5_Items USING(ThreadID) WHERE Thread IS NULL 
-</code>