SQL Question

bragan

Does anyone know what *= in SQL is used for?
An example of its use would be:

select name, age, d.address
from Details d, names n
where n.age *= d.age

Im thinking its the same as the LIKE operator except for use with numeric data.
Anyone know??

Hobbes

Would it be the same as...

n.age = n.age * d.age

dunno

bragan

maybe. im not to sure. i don't think there trying to multipy in the statement though

Basq

Am presuming * is the wildcard character in that statement.

bragan

yeah, so by doing wildcard equals its saying
if n.age is like or equal d.age ??

long_b

It's a type of Join ...

"Transact-SQL Joins
In earlier versions of Microsoft® SQL Server™ 2000, left and right outer join conditions were specified in the WHERE clause using the *= and =* operators. In some cases, this syntax results in an ambiguous query that can be interpreted in more than one way. SQL-92 compliant outer joins are specified in the FROM clause and do not result in this ambiguity. Because the SQL-92 syntax is more precise, detailed information about using the old Transact-SQL outer join syntax in the WHERE clause is not included with this release. The syntax may not be supported in a future version of SQL Server. Any statements using the Transact-SQL outer joins should be changed to use the SQL-92 syntax.

The SQL-92 standard does support the specification of inner joins in either the FROM or WHERE clause. Inner joins specified in the WHERE clause do not have the same problems with ambiguity as the Transact-SQL outer join syntax."

bragan

ok, thanks

amen

as mentioned *= and =* are hang overs from MS SQL 7 and prior versions.
Bad habit you shoould rewrite the code
if you find any
A:
Select
MyName = FirstNAme
From Customers
then you should really rewrite
as
B:
Select
FirstNAme AS MyName
From Customers

as again A: is a MS thingy and not ANSI compliant