Left table data Right table multiple returns

Question

Hello all and thank you for taking the time to help.
I have a left table and right table I am querying from 2 remote hosts. The information in the left table is unique and has everything I need except for 2 fields; the information in the right table can have multiple rows for the same identifier. I am trying to get the latest rows information on the right. This is a snapshot of the tables:
Employee Table
  Emp_num       Emp_Name   Emp_Store     Emp_Category     Emp_Location
  W561789        Chris           R79                Sales     98-778-77
  W571779        Charles           R81                Sales     87-988-98
  W561874        Sam           R79                Management     76-977-97
W561875        Tod           R79                Sales     98-778-77
Customers Table
  Emp_num    Wait_Time  Shipment_Status      Shipment_Date
  W561789     1
  W561789                          Shipped               2/28/2011
  W561789                          On_Order             2/27/2011
  W561875                          On_Order             2/27/2011What I am trying to pull is specific information from the Employee table, and only the most recent matching record from the Customer table. My query looks something like this (it doesn't work, or it takes a really long time to run)
SELECT
    D.EMP_NUM, D.EMP_NAME,D.EMP_STORE, D.EMP_CATEGORY, D.EMP_LOCATION, M.SHIPMENT_STATUS, M.WAIT_TIME
FROM
    DB1.TABLE1@HOST_A_LINK  D,
       (SELECT EMP_NU, SHIPMENT_STATUS, WAIT_TIME,
                         ROW_NUMBER() OVER(PARTITION BY EMP_NUM ORDER BY SHIPMENT_DATE) rownumber
             FROM DB1.TABLE10@HOST_B_LINK) M
WHERE D.EMP_NUM=M.EMP_NUM
AND rownumber=1
AND D.EMP_STORE='R79'
AND D.EMP_CATEGORY IN ( 'Sales',
     'Management',
     'Supervisor')
AND D.EMP_LOCATION IN ( '98-778-77', '87-988-98')thanks

Answer 1

Just to close the loop on this question, I figured it out. I had to move the ROW_NUMBER() alias outside the scope of the WHERE clause. The query looks like this:
SELECT
         D.EMP_NUM,
         D.EMP_NAME,
         D.EMP_STORE,
         D.EMP_CATEGORY,
         D.EMP_LOCATION,
         M.SHIPMENT_STATUS,
         M.WAIT_TIME
FROM
    DB1.TABLE1@HOST_A_LINK  D,
       (SELECT
        FROM
                (SELECT
                            EMP_NU,
                            SHIPMENT_STATUS,
                            WAIT_TIME,
                            ROW_NUMBER() OVER(PARTITION BY EMP_NUM ORDER BY SHIPMENT_DATE) AS rownumber
                 FROM
                           DB1.TABLE10@HOST_B_LINK
        WHERE rownumber=1) M
WHERE
      D.EMP_NUM(+)=M.EMP_NUM
      AND rownumber=1
      AND D.EMP_STORE='R79'
      AND D.EMP_CATEGORY IN ( 'Sales',
                                   'Management',
                                   'Supervisor')
      AND D.EMP_LOCATION IN ( '98-778-77', '87-988-98')