I need help with a SQL Query. SQL beginner here!
The columns in common, do not have to have the same name, they just need to have the same data.


  I've done a little research into join clauses, but don't there need to be at least one column in common between the tables? I've been analyzing the output from Queries that show the column names from both tables. There are NO common column names. There is, however, a column in each table that has the same data but different column names.


The easiest way to get started in SSMS (SQL Server Management Studio) is to use the it to get the basics of your query. Then fine tune it, be editing the code, it makes for you.

Go to the table, right click on the table name, select option "Select top 1000 rows. this will create the beginning of your query, and you can edit it until it gets you what you want.  If this is a production system you might want to limit to the top 25 until you get your query working well. 

SELECT TOP (25) [ARInvoiceDetails].[ArDetPriceLevelID]
, [ARInvoiceHdr].[ArInvPriceLevelID]
  FROM [ARInvoiceDetails]
  LEFT JOIN [ARInvoiceHdr]
  ON [ARInvoiceDetails].[ArDetPriceLevelID] = [ARInvoiceHdr].[ArInvPriceLevelID]