Add Data from Columns Together I am working on importing data from an old non-relational database, to a new relational one.  I am currently working on importing data into the following table:
Table: job_part
    job_id   INT NOT NULL --References ID Column of Job table
    part_id  INT NOT NULL --References ID Column of Part table
    quantity INT NOT NULL --Amount of parts required for the job
    PK = job_id &amp; part_id

The data I have is in a .csv file which has the following columns;

Part Number - Value will be referenced with Part table to get part_id value
Job Number - Value will be referenced with Job table to get job_id value
Amount - Value to be stored in Quantity column

My problem is when there are data rows like the following:
CDDM 42, P0164, 1
CDDM 42, P0164, 2

As you can see, the Part Number, and Job Number are the same, while the quantity value is different.  Because the table I want to insert this data into has the PartID and JobID as a composite primary key, these pieces of data will give me an error when I try to import it.
What I want to do, is to take this data, and before I put it in my table, put it into a temporary table that combines all of the matching key pairs.  So for my problem example above, instead of having the two rows that will cause and error I want the result to be:
CDDM 42, P0164, 3

Essentially, find every matching pair of key values, and add their quantities together so they can be a single row of data.
However I am unsure how to go about solving this problem.  I am using SQL Server.
You answered your own question, by importing it into a temporary or staging table. 

CREATE TABLE #TempTable(
    job_id   INT NOT NULL
    ,part_id  INT NOT NULL 
    ,quantity INT NOT NULL)

BULK INSERT #TempTable
FROM 'C:\example.csv'
WITH
(FIELDTERMINATOR = ',',
ROWTERMINATOR = '\n') --any other options like FIRSTROW, etc


Then, just use the SUM() aggregate when inserting into your actual table

INSERT INTO MyTable
SELECT 
   job_id   
   ,part_id  
   ,quantity = SUM(quantity) 
FROM #TempTable
GROUP BY
   job_id   
   ,part_id