Access SQL LEFT JOIN alternative - sql

Question

I'm trying something in Access via SQL using a LEFT JOIN but it doesn't seem to be working. Access keeps generating the error "JOIN expression not supported.".
What I'm trying to accomplish is as follows. I have a table with job cards and another table with costs as below.
JOBCARDS
ID JOBNAME
1 Job one
2 Job two
3 Job three
COSTS
ID TYPE COST JOB
1 PART 15.01 1
2 LABOUR 20.00 1
3 LABOUR 40.00 2
4 PART 34.54 3
5 PART 84.67 3
I'm trying to formulate an SQL query that will give me the following result:
QUERY
ID JOBNAME PARTS LABOUR
1 Job one 15.01 20.00
2 Job two 0.00 40.00
3 Job three 119.21 0.00
What I came up with:
SELECT
CARDS.[ID] AS [ID],
CARDS.[JOBNAME] AS [JOBNAME],
SUM (COSTS1.[COST]) AS [PARTS],
SUM (COSTS2.[COST]) AS [LABOUR]
FROM
(([JOBCARDS] CARDS LEFT JOIN [COSTS] COSTS1 ON COSTS1.[JOB]=CARDS.[ID] AND COSTS1.[TYPE]='PART')
LEFT JOIN [COSTS] COSTS2 ON COSTS2.[JOB]=CARDS.[ID] AND COSTS2.[TYPE]='LABOUR')
GROUP BY
CARDS.[ID], CARDS.[JOBNAME];
Access seems to be having problems with the part "COSTS1.[TYPE]='PART'".
Is there any way I can accomplish what I'm trying to do without using a LEFT JOIN?
Or does anyone spot the error?

Answer 1

This SQL will give the result.
The 0 values will be Null, but you could use NZ to replace that with a 0.
SELECT JobCards.ID
,JobName
,SUM(C2.Cost) AS Parts
,SUM(C1.Cost) AS Labour
FROM (JobCards LEFT JOIN Costs C1 ON (JobCards.ID = C1.Job AND C1.Type = 'Labour'))
LEFT JOIN Costs C2 ON (JobCards.ID = C2.Job AND C2.Type = 'Part')
GROUP BY JobCards.ID
,JobName
Edit:
Re-reading your SQL - you just forgot to put the brackets after the ON statements in your Join:
(COSTS1.[JOB]=CARDS.[ID] AND COSTS1.[TYPE]='PART')
SELECT
CARDS.[ID] AS [ID],
CARDS.[JOBNAME] AS [JOBNAME],
SUM (COSTS1.[COST]) AS [PARTS],
SUM (COSTS2.[COST]) AS [LABOUR]
FROM
(([JOBCARDS] CARDS LEFT JOIN [COSTS] COSTS1 ON (COSTS1.[JOB]=CARDS.[ID] AND COSTS1.[TYPE]='PART'))
LEFT JOIN [COSTS] COSTS2 ON (COSTS2.[JOB]=CARDS.[ID] AND COSTS2.[TYPE]='LABOUR'))
GROUP BY
CARDS.[ID], CARDS.[JOBNAME];
Edit 2: There's no need to put brackets around everything, or alias the field names if they're the same as the source field, or use the table names in the SELECT & WHERE clauses unless the field name appears in more than one table.

Answer 2

Here is a correlated sub-query example:
SELECT JOBCARDS.ID,
JOBCARDS.JOBNAME,
(SELECT SUM([COST]) FROM COSTS WHERE COSTS.JOB = JOBCARDS.ID AND COSTS.TYPE = 'PART') AS PARTS,
(SELECT SUM([COST]) FROM COSTS WHERE COSTS.JOB = JOBCARDS.ID AND COSTS.TYPE = 'LABOUR') AS LABOUR
FROM JOBCARDS;