Friday, March 20, 2015

SQL-89 versus SQL-90 JOIN Syntax - What's the Difference???

What's the advantage of using the "JOIN" syntax when joining SQL tables???

I work in a mixed environment where we use both SQL Servers and Sybase Servers.

All of the SQL Server developers write their joins using the SQL-92 syntax like this:

    SELECT c.name, a.state FROM 
        Customers c JOIN Address a ON c.CustomerId = a.CustomerId

But all of the Sybase developers continue to write their joins using the SQL-89 syntax like this:

    SELECT c.name, a.state FROM Customers c, Address a
        WHERE c.CustomerId = a.CustomerId

I don't see much difference on these smaller queries, but I always get frustrated trying to read the SQL-89 syntax on larger queries.  What's the difference and why do developers still use SQL-89 syntax???