INNER JOIN vs multiple table names in "FROM" [duplicate]

Question

Possible Duplicate:
INNER JOIN versus WHERE clause — any difference?

What is the difference between an INNER JOIN query and an implicit join query (listing multiple tables after the FROM keyword)? For example:

Given the following two tables:

CREATE TABLE Statuses(   id INT PRIMARY KEY,   description VARCHAR(50) ); INSERT INTO Statuses VALUES (1, 'status');  CREATE TABLE Documents(   id INT PRIMARY KEY,   statusId INT REFERENCES Statuses(id) ); INSERT INTO Documents VALUES (9, 1); 

What is the difference between these two SQL queries? From the testing I've done, they return the same result. Do they do the same thing? Are there situations where they will return different result sets?

SELECT s.description FROM Documents d, Statuses s WHERE d.statusId = s.id AND d.id = 9;  SELECT s.description FROM Documents d INNER JOIN Statuses s ON d.statusId = s.id WHERE d.id = 9; 

Answer 1

If you do it the first way, people under the age of 30 will probably chuckle at you, but as long as you're doing an inner join, they produce the same result and the optimizer will generate the same execution plan (at least as far as I've ever been able to tell).

This does of course presume that the where clause in the first query is how you would be joining in the second query.

This will probably get closed as a duplicate, btw.