Refresh field based on other table values

Question

Is there a more elegant way to write the following Microsoft SQL Server 2008 command?

UPDATE TableB SET TableBField2=0 WHERE TableBID IN( SELECT TableBID FROM TableB JOIN TableA on TableB.TableAID=TableA.TableAID WHERE TableBField2 < 0 AND TableAField1 = 0 ) 

In simple terms, I am updating a table based on the value of a field in a joined table. I wonder if my use of IN () is not considered inefficient.

Answer 1

This should be more efficient:

 UPDATE TableB b SET TableBField2=0 WHERE exists ( SELECT 1 FROM TableA WHERE b.TableAID=TableA.TableAID AND b.TableBField2 < 0 AND TableAField1 = 0 ) 

Answer 2

You can try something like this

 UPDATE TableB SET Field2 = 0 FROM TableB b INNER JOIN TableA a ON b.TableB.TableAID=a.TableAID WHERE b.Field2 < 0 AND a.Field1 = 0