Yes, it a vice versa. It depends on which side of the relationship the entity is present on. For example, if one department can employ for several employees then, department to employee is a one to many relationship (1 department employs many employees), while employee to department relationship is many to one (many employees work … Read more
You could try some sort of COALESCE trick, eg: SELECT COALESCE( CASE WHEN condition1 THEN calculation1 ELSE NULL END, CASE WHEN condition2 THEN calculation2 ELSE NULL END, etc… )
You can try below query,
o to the windows machine that hosts the Oracle database server Go to Start -> Run -> Services.msc in Windows. Locate OracleService < SID > (here OracleServiceORCL) and click on Start to start the oracle database service (if not already running) Once it is up and running, from the command prompt run the following:tnsping < tnsalias > (tnsalias entry you can … Read more
They are functionally equivalent, but INNER JOIN can be a bit clearer to read, especially if the query has other join types (i.e. LEFT or RIGHT or CROSS) included in it.
SQL is primarily a set-orientated language – it’s generally a bad idea to use a loop in it. In this case, a similar result could be achieved using a recursive CTE:
This basically is a pivot table. A nice tutorial on how to achieve this can be found here: http://www.artfulsoftware.com/infotree/qrytip.php?id=78 I advise reading this post and adapt this solution to your needs. Update After the link above is currently not available any longer I feel obliged to provide some additional information for all of you searching for mysql pivot … Read more
Just as the error says, the CREATE VIEW statement needs to be the only statement in the query batch. You have two option in this scenario, depending on the functionality you want to achieve: Place the CREATE VIEW query at the beginningCREATE VIEW showing as select tradename, unitprice, GenericFlag from Medicine; with ExpAndCheapMedicine(MostMoney, MinMoney) as ( select max(unitprice), min(unitprice) … Read more
Composite indexes work just like regular indexes, except they have multi-values keys. If you define an index on the fields (a,b,c) , the records are sorted first on a, then b, then c. Example: