Is there a way to SELECT prevent duplicates when using the Sum function in MS Access?
I have tried:

A lot of work went into this question, so please let me know if i need to add something.

Im writing query for access. It says that im missing operator in Client.Id=O.ClientId INNER JOIN [OrderDish] AS OD ON O.Id=OD.OrderI`

I have two tables in access, with 2 columns in each. Column A and B in table 1. Column C and D in table 2.

I’d like to ask for your assistance regarding a requirement that I want to achieve.I’m not exactly sure on how to approach this query.

I’m new to this forum, am a novice using Access/SQL and I appreciate any help people can give me. I’m using MS access and trying to use SQL to join 2 tables by customer name. Each table has columns of first and last name. However as many of you have probably experienced names are not unique and sometimes people use their formal name such as William, sometimes a nickname like Bill. I was wondering if I can somehow join the 2 existing tables with a 3rd table that contains of list of nicknames such as William/Bill, Mike/Michael etc. and have the query show results if either of the 2 names in the 3rd table match either name in the first 2 tables. There are no unique ID’s for the customers. Hope I’m making sense. Thoughts on this, or has anyone come up with a better approach?

I’m trying to import data from csv files into one table which consolidates the data and counts occurances of failing some tests.
Nearly all the work is done, except for the fact that now i can import the same data multiple times and it simply appends it to the bottom of my table.

I have 2 tables AudioInfo and Dev as shown below on MSAccess: