SQL Statement - Too dumb to figure it out - sql-server-2008

Question

I have a working knowledge of SQL Server along with the ability to perform most basic queries. However, I'm stuck and needs some help with this one. I have 6 related tables from which I need to derive a set of data.
Tables are as follows:
MTMeterReadings mr
Actual
GroupID
MeterID
CreateDate
MTMeterReadingGroups mg
MeterReadingGroupID
MeterSourceID
EquipmentID
MTMeterSources ms
MeterSourceID
Description
MTMeters m
MeterID
Description
SCEquipment eq
EquipmentID
CustomerID
ARCustomers c
CustomerID
CustomerName
My desired result set is to show the following data for each Actual record in the MTMeterReadins table where mr.CreateDate > 'mm/dd/yyy':
mr.actual | mr.CreateDate | ms.description | e.EquipmentID | c.CustomerName
So far, I've been able to create a query with everything I need except c.CustomerName, but just can't seem to take it all the way (I can be JOIN challenged at times).
Any help with this is greatly appreciated.
I apologize, but I didn't know if the query I already had would be helpful or not.
Here is what I have that yields everything I want except customer name:
SELECT
mg.EquipmentID,
CAST(mr.Actual AS decimal(12, 0)) AS Meter,
CAST(mr.CreateDate AS DATE) AS MeterDate,
ms.MeterSource, m.Description
FROM
MTMeterReadings AS mr
INNER JOIN
MTMeterReadingGroups AS mg ON mr.MeterReadingGroupID = mg.MeterReadingGroupID
INNER JOIN
MTMeterSources AS ms ON mg.MeterSourceID = ms.MeterSourceID
INNER JOIN
MTMeters AS m ON mr.MeterID = m.MeterID
WHERE
(mr.CreateDate >= '01/01/2014') AND (mr.CreateDate <= '02/20/2015')
ORDER BY
MeterDate DESC, mg.EquipmentID, m.Description
However, every attempt that I have made to add CustomerName yields a multiple of the records that I have in the mr table. I can't tell exactly what my error is, but I'm assuming it is an incorrect join. Maybe simple for someone with a bigger SQL brain than me, but this is far from being inside my core knowledge base as I learned SQL from a SAMS "Teach Yourself SQL in 10 Minutes" book.

Answer 1

You are missing additional 2 joins:
SELECT mg.EquipmentID, CAST(mr.Actual AS decimal(12, 0)) AS Meter, CAST(mr.CreateDate AS DATE) AS MeterDate, ms.MeterSource, m.Description, ar.CustomerName
FROM MTMeterReadings AS mr INNER JOIN
MTMeterReadingGroups AS mg ON mr.MeterReadingGroupID = mg.MeterReadingGroupID INNER JOIN
MTMeterSources AS ms ON mg.MeterSourceID = ms.MeterSourceID INNER JOIN
MTMeters AS m ON mr.MeterID = m.MeterID
INNER JOIN SCEquipment eq on mg.EquipmentID = eq.EquipmentID
INNER JOIN ARCustomers ar on eq.CustomerID = ar.CustomerID
WHERE (mr.CreateDate >= '01/01/2014') AND (mr.CreateDate <= '02/20/2015')
ORDER BY MeterDate DESC, mg.EquipmentID, m.Description

Answer 2

It should be as simple as this:
SELECT mg.EquipmentID,
CAST(mr.Actual AS DECIMAL(12, 0)) AS Meter,
CAST(mr.CreateDate AS DATE) AS MeterDate,
ms.MeterSource,
m.Description
c.CustomerName
FROM MTMeterReadings AS mr INNER JOIN
MTMeterReadingGroups AS mg ON mr.MeterReadingGroupID = mg.MeterReadingGroupID INNER JOIN
MTMeterSources AS ms ON mg.MeterSourceID = ms.MeterSourceID INNER JOIN
MTMeters AS m ON mr.MeterID = m.MeterID INNER JOIN
SCEquipment AS e ON mg.EquipmentID = e.EquipmentID INNER JOIN
ARCustomers AS c ON e.CustomerID = c.CustomerID
WHERE (mr.CreateDate BETWEEN '01/01/2014' AND '02/20/2015')
ORDER BY MeterDate DESC,
mg.EquipmentID,
m.Description
But that's assuming that there are no possible outer joins and that every relation you want has at least one record.
Also, note that if mr.CreateDate is a datetime you will miss times on 2/20/2015 after midnight.