CODEWITHSUNDEEP
sqlsql-server
huynq9
huynq9

Reputation: 542

the different between join condition and where condition

Somebody tell me what's the difference between two queries:

Version A

select p.LastName, o.OrderNo  
  from Persons p, Orders o  
 where p.P_Id = o.P_Id

...and...

Version B

select p.LastName, o.OrderNo  
  from Persons p 
  join Orders o on p.P_Id = o.P_Id

Upvotes: 2

Views: 252

Answers (2)

OMG Ponies
OMG Ponies

Reputation: 332591

Both use an INNER JOIN to combine records between the PERSONS and ORDERS tables. Version A is ANSI-89 syntax, and Version B is ANSI-92 syntax.

There's no performance difference between them, but the ANSI-92 syntax supports OUTER JOINs (LEFT, RIGHT, and FULL depending on the database) while the ANSI-89 does not.

Upvotes: 8

akonsu
akonsu

Reputation: 29536

assuming that "join" is a shorthand syntax for "inner join" i see no difference.

Upvotes: 0

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