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Databases

Josh Bennett
Josh Bennett
15,258 Points
Posted by Josh Bennett
Josh Bennett
15,258 Points

how does adding the aliases here make the code "cleaner"? it works the same without the additional mk. and md. 

SELECT mk.MakeName, md.ModelName FROM make AS MK 
  INNER JOIN model AS md 
  ON mk.MakeID = md.MakeID;

produces the same result as 

SELECT MakeName, ModelName FROM make AS MK 
  INNER JOIN model AS md 
  ON mk.MakeID = md.MakeID;

and

SELECT mk.MakeName, md.ModelName FROM make 
  INNER JOIN model 
  ON make.MakeID = model.MakeID;

so what gives??

1 Answer

Steven Parker
Steven Parker
231,271 Points
Steven Parker
Steven Parker
231,271 Points

:point_right: This might not be the best example for showing the advantages of aliases.

First off, your samples don't look like they would work, as they both contain references to aliases that are not defined.

But I'll assume those are just typo's and I get your point — there's not much difference in the code and no difference at all in the output when using the aliases.

Cases where using aliases are more advantageous would include:

  • when the joined tables have columns with the same names, which would otherwise be ambiguous
  • when the table names are much longer than the chosen aliases
  • when the number of selected columns is very large and the source table for each is not obvious