SQL Select, Match one column but not another

I have two tables in an SQL Server 2008 R2 database, lets call them A and B. They look like this

A
--------------------
GUID     Primary Key
B_GUID   Foreign Key
Value    nvarchar(50)

B
--------------------
GUID     Primary Key
Value    nvarchar(开发者_开发技巧50)

I want to select all rows from A where

• B_GUID in A matches GUID in B
• Value in A does not match Value in B

However, I can't figure out the SQL. Any help? :) Thanks

---

How about:

SELECT A.*
FROM dbo.A
INNER JOIN dbo.B ON A.B_GUID = B.GUID
WHERE
    A.Value <> B.Value

The INNER JOIN matches the two tables together, on equality of those two columns, and the WHERE clause restricts it further to just two rows where that condition applies.

---

select 
  A.*
from
  A
join
  B on A.B_GUID = B.GUID and A.Value <> B.Value

---

SELECT * 
FROM A 
LEFT JOIN B
ON A.B_GUID = B.GUID  WHERE A.Value <> B.Value;

This is not tested but should work

---

Note, there could be a possible drawback on above answers depending upon the situation: Say if you have records as below even though there is a matching record due to other none matching record you will find the output as mismatch.

TABLE 1     
GUID    B_GUID  VALUE
101 201 X
102 201 Y

TABLE2      
GUID    VALUE   
201 Y   
201 X   

One alternate way to solve this is use EXCEPT clause query.