SQL – JOIN vs. INNER JOIN and FULL OUTER JOIN

sqlsql server

I know there is a difference between INNER JOIN and FULL OUTER JOIN, I can see it, but, what is the difference between the two following: JOIN ... ON... and INNER JOIN...ON... and still yet JOIN...ON... vs FULL OUTER JOIN...ON...

Reason being is I think maybe just using JOIN is messing up a query I am working on that is posted on SO, link to question HERE.

So basically what is the syntactical difference between the actual set operations themselves?

Thank You,

Best Answer

JOIN and INNER JOIN are the same, the inner keyword is optional as all joins are considered to be inner joins unless otherwise specified. The difference between JOIN and FULL OUTER JOIN is the same as the difference between INNER JOIN and FULL OUTER JOIN.

An INNER JOIN will only return matched rows if a row in table A matches many rows in table B the table A row will be repeated with each table B row and vice versa.

A FULL OUTER JOIN will return everything an inner join does and return all unmatched rows from each table.

Related Topic