Sql server® 2012 t-sql fundamentals

anSI SQL-89 Syntax

SQL Server also supports an older syntax for cross joins that was introduced in ANSI SQL-89. In this 

syntax you simply specify a comma between the table names, like this.

SELECT C.custid, E.empid 

FROM Sales.Customers AS C, HR.Employees AS E;

There is no logical or performance difference between the two syntaxes. Both syntaxes are integral 

parts of the latest SQL standard (ANSI SQL:2011 at the time of this writing), and both are fully sup-

ported by the latest version of SQL Server (Microsoft SQL Server 2012 at the time of this writing). I am 

not aware of any plans to deprecate the older syntax, and I don’t see any reason to do so while it’s an 

integral part of the standard. However, I recommend using the ANSI SQL-92 syntax for reasons that 

will become clear after inner joins are explained.