Access 2010 doubling the sum in query

Question

I know this question has been asked and answered. I understand the problem and I understand the underlying cause and I understand the solution. What I DON'T understand is how to implement the solution.

I'll try to be detailed....

Background: Each material is being grouped on WellID (I work in oil and gas) and SandType which is my primary key in each table, these come from 2 lookup tables one for each. (I work in oil and gas)

I have 3 tables that store material (sand)) weights at 3 different stages in the job process. Basically the weight from the engineer's DESIGN, what was DELIVERED and what is in INVENTORY.

I know that the join is messed up and adding the total for each row in each table. Sometimes double triple etc.

I am grouping on WellID and SandID.

Now I don't want someone to do the work for me. I just don't know how or where in access to restrict it to what I want, or if modifying t he sql the proper way to write the code. Current work around is 3 separate sum queries one for each table, but that is going to get inefficient and added steps.

My whole database purpose and subsequent reports hinge off math on these 3 numbers so, my show stopper here is putting the fat lady on stage, and is about to become a deal breaker at the end of the line! 0

I need some advice, direction, criticism, wisdom, witty euphemisms or a new job!

The 3 tables look as follows

Design: 
T_DESIGN

DesignID    WellID  Sand_ID     Weight_DES    Time_DES
89  201 1   100 4/21/2014 6:46:02 AM
98  201 2   100 4/21/2014 7:01:22 AM
86  201 4   100 4/21/2014 6:28:01 AM
93  228 5   100 4/21/2014 6:53:34 AM
91  228 1   100 4/21/2014 6:51:23 AM
92  228 1   100 4/21/2014 6:53:30 AM


Delivered:
T_BOL

BOLID   WellID_BOL  SandID_BOL  Weight_BOL
279 201 1   100
280 201 1   100
281 228 2   5
282 228 1   10
283 228 9   100


Inventory:
T_BIN

StrapID WellID_BIN  SandID_BIN  Weight_BIN
11  201 1   100
13  228 1   10
14  228 1   0
17  228 1   103
19  201 1   50

The Query Results:

Test Query99


WellID

WellID  SandID  Sum Of Weight_DES   Sum Of Weight_BOL   Sum Of Weight_BIN
201 1   400                   400             300
228 1   600                    60           226

SQL:

SELECT DISTINCTROW L_WELL.WellID, L_SAND.SandID, 
Sum(T_DESIGN.Weight_DES) AS [Sum Of     Weight_DES], 
Sum(T_BOL.Weight_BOL) AS [Sum Of Weight_BOL],
Sum(T_BIN.Weight_BIN) AS [Sum Of   Weight_BIN]
FROM ((L_SAND INNER JOIN 
  (L_WELL INNER JOIN T_DESIGN ON L_WELL.[WellID] = T_DESIGN.[WellID_DES]) 
  ON L_SAND.SandID = T_DESIGN.[SandID_DES]) 
  INNER JOIN T_BIN 
  ON (L_WELL.WellID    = T_BIN.WellID_BIN) 
  AND (L_SAND.SandID = T_BIN.SandID_BIN)) 
  INNER JOIN T_BOL 
  ON   (L_WELL.WellID = T_BOL.WellID_BOL) AND (L_SAND.SandID = T_BOL.SandID_BOL)
GROUP BY L_WELL.WellID, L_SAND.SandID;

Two LooUp tables are for Well Names and Sand Types. (Well has been abbreviate do to size)

L_Well:

WellID  WellName_WELL
3   AAGVIK  1-35H
4   AARON  1-22
5   ACHILLES   5301 41-12B
6   ACKLINS  6092 12-18H
7   ADDY   5992 43-21 #1H
8   AERABELLE  5502 43-7T
9   AGNES  1-13H
10  AL  5493 44-23B
11  ALDER  6092 43-8H
12  AMELIA FEDERAL  5201 41-11B
13  AMERADA STATE     1-16X
14  ANDERSMADSON  5201 41-13H
15  ANDERSON  1-13H
16  ANDERSON  7-18H
17  ANDRE  5501 13-4H
18  ANDRE  5501 14-5 3B
19  ANDRE SHEPHERD  5501 14-7 1T

Sand Lookup:

LSand

SandID  SandType_Sand
1   100 Mesh
2   20/40 EP
3   20/40 RC
4   20/40 W
5   30/50 Ceramic
6   30/50 EP
7   30/50 RC
8   40/70 EP
9   40/70 W
10  NA See Notes

Answer 1

Querying and Joining Aggregation Data through an MS Access Database

I noticed your concern for pointers on how to implement some of the theory behind your aggregation queries. While SQL queries are good power-tools to get to the core of a difficult analysis problem, it might also be useful to show some of the steps on how to bring things together using the built-in design tools of MS Access.

This solution was developed on MS Access 2010.

Comments on Previous Solutions

@xQbert had a solid start with the following SQL statement. The sub query approach could be visualized as individual query objects created in Access:

FROM 
    (SELECT WellID, Sand_ID, Sum(weight_DES) as sumWeightDES
       FROM T_DESGN) A
INNER JOIN 
    (SELECT WellID_BOL, Sum(Weight_BOL) as SUMWEIGHTBOL
       FROM T_BOL B) B
    ON A.Well_ID = B.WellID_BOL
INNER JOIN 
    (SELECT WellID_BIN, sum(Weight_Bin) as SumWeightBin
       FROM T_BIN) C
    ON C.Well_ID_BIN = B.Well_ID_BOL 

Depending on the actual rules of the business data, the following assumptions made in this query may not necessarily be true:

• Will the tables of T_DESIGN, T_BOL and T_BIN be populated at the same time? The sample data has mixed values, i.e., there are WellID and SandID combinations which do not have values for all three of these categories.

• INNER type joins assume all three tables have records for each dimension value (Well-Sand combination)

@Frazz improved on the query design by suggesting that whatever is selected as the "base" joining table (T_DESIGN in this case), this table must be populated with all the relevant dimensional values (WellID and SandID combinations).

SELECT
    WellID_DES AS WellID,
    SandID_DES AS SandID,
    SUM(Weight_DES) AS Weight_DES,
(SELECT SUM(Weight_BOL) FROM T_BOL WHERE T_BOL.WellID_BOL=d.WellID_DES 
    AND T_BOL.SandID_BOL=d.SandID_DES) AS Weight_BOL,
(SELECT SUM(Weight_BIN) FROM T_BIN WHERE T_BIN.WellID_BIN=d.WellID_DES 
    AND T_BIN.SandID_BIN=d.SandID_DES) AS Weight_BIN

FROM T_DESIGN;
(... note: a group-by statement should be here...)

• This was animprovement because now all joins originate from a single point. If a key-value does not exist in either T_BOL or T_BIN, results will still come back and the entire record of the query would not be lost.

• Again, it may be possible that there are no T_DESIGN records matching to values stored in the other tables.

Building Aggregation Sub Query Objects

The presented data does not suggest that there is any direct interaction between the data in each of the three tables aside from lining up their results in the end for presentation based on a common key-value pair (WellID and SandID). Since we are using Access, there is a chance to do these calculations separately.

This query was designed using the "summarizing" feature of the Access query design tool. It's output, after pointing to the T_DESIGN table looked like this:

Making Dimension Table Through a Cartesian Product

There are mixed opinions out there about cartesian products, but they do actually have a purpose.

Most of the concern is that a runaway cartesian product query will make millions and millions of nonsensical data values. In this query, it's specifically designed to simulate a real business condition.

The Case for a Cartesian Product

Picking from the sample data provided:

• Some of the Sand Types: "20/40 EP", "30/50 Ceramic", "40/70 EP", and "30/50 RC" that are moved between their respective wells, are these sand types found at these wells consistently throughout the year?

• Without an anchoring dimension for the key-values, Wells would not be found anywhere in the database via querying. It's not that they do not exist... it's just that there is no recorded data (i.e., Sand Type Weights delivered) for them.

A Reference Dimension Query Product

A dimension query is simple to produce. By referencing the two sources of keys: L_WELL and L_SAND (both look up tables or dimensional tables) without identifying a join condition, all the different combinations of the two key-values (WellID and SandID) are made:

The shortcut in SQL looks like this:

SELECT L_WELL.WellID, L_SAND.SandID, L_WELL.WellName, L_SAND.SandType
  FROM L_SAND, L_WELL;

The resulting data looks like this:

Instead of using any of the operational data tables: T_DESIGN, T_BOL, or T_BIN as sources of data for a static dimension such as a list of Oil Wells, or a catalog of Sand Types, that data has been predetermined and can even be transferred to a real table since it probably will not change much once it is created.

Correlating Sub Query Results from Different Sources

After repeating the process and creating the summary tables for the other two sources (T_BOL and T_BIN), You can finally arrange the results through a simple query and join process.

The actual JOIN operations are between the dimension table/query: QSUB_WELL_SAND and all three of the summary queries: QSUB_DES, QSUB_BOL, and QSUB_BIN.

I have chosen to chosen to implement LEFT OUTER joins. If you are not sure of the difference between the different "outer" joins, this is the choice I made through the Access Query Design dialogue:

QSUB_WELL_SAND is defined as our anchor dimension. It will always have more records than any of the other tables. An OUTER JOIN should be defined to KEEP all reference dimension records... and all Summary Table query results, regardless if there is a match between the two Query results.

QSUB_WEIGHTS/ The Query to Combine All Sub Query Results

This is what the design of the final output query looks like:

This is what the data output looks like when this query design is executed:

Conclusions and Clean Up: Some Closing Thoughts

With respect to the join to the dimension query, there is a lot of empty space where there are no records or data to report on. This is where a cleverly placed filter or query criteria can shrink the output to exactly what you care to look at the most. Here's how mine looked after I added additional ending query criteria:

My data was based on what was supplied by the OP, except where the ID's assigned to the Well Type attribute did not match the sample data. The values I assigned instead are posted below as well.

Access supports a different style of database operations. Step-wise queries can be developed to hold pre-processed, special sets of data that can be reintroduced to the other data tables and query results to develop complex query criteria.

All this being said, Programming in SQL can also be just as rewarding. Be sure to explore some of the differences between the results and the capabilities you can tap into by using one approach (sql coding), the other approach (access design wizards) or both of the approaches. There's definitely a lot of room to grow and discover new capabilities from just the example provided here.

Hopefully I haven't stolen all the fun from developing a solution for your situation. I read into your comment about "building more on top" as the harbinger of more fun to come, so I don't feel so bad...! Happy Developing!

Data Modifications from the Sample Set

Answer 2

Without understanding L_SAND and L_WELL this is the best I could come up with.. use sub selects to get the sums first so you don't compound the data issues on the joins.

Select WellID, Sand_ID, sumWeightDES, WellID_BOL, SUMWEIGHTBOL, 
WellID_BIN, SumWeightBin
FROM 
(SELECT WellID, Sand_ID, Sum(weight_DES) as sumWeightDES
FROM T_DESGN) A
INNER JOIN 
(SELECT WellID_BOL, Sum(Weight_BOL) as SUMWEIGHTBOL
FROM T_BOL B) B
 ON A.Well_ID = B.WellID_BOL
INNER JOIN 
(SELECT WellID_BIN, sum(Weight_Bin) as SumWeightBin
FROM T_BIN) C
ON C.Well_ID_BIN = B.Well_ID_BOL

Answer 3

I would simplify it excluding L_WELL and L_SAND. If you are just interestend in IDs, then they really shouldn't be necessary joins. If all the other 3 tables have the WellID and SandID columns, then pick the one that is sure to have all combos.

Supposing it's the Design table, then:

SELECT
  WellID_DES AS WellID,
  SandID_DES AS SandID,
  SUM(Weight_DES) AS Weight_DES,
  (SELECT SUM(Weight_BOL) FROM T_BOL WHERE T_BOL.WellID_BOL=d.WellID_DES AND T_BOL.SandID_BOL=d.SandID_DES) AS Weight_BOL,
  (SELECT SUM(Weight_BIN) FROM T_BIN WHERE T_BIN.WellID_BIN=d.WellID_DES AND T_BIN.SandID_BIN=d.SandID_DES) AS Weight_BIN
FROM T_DESIGN
GROUP BY WellID, SandID;

... and make sure all your tables have an index on WellID and SandID.

Just to be clear. I dont' think it's a good idea to start the join from the lookup tables, or from their cartesian product. You can always left join them to fetch descriptions and other data. But the main query should be the one with all the combos of WellID and SandID... or if not all, at least the most. Things get difficult if none of the 3 tables (DESIGN, BOL and BIN) have all combos. In that case (and I'd say only in that case) then you might as well start with the cartesian product of the two lookup tables. You could also do a UNION, but I doubt that would be more efficient.