How to determine which columns are shared between two tables?

Question

Very new to SQL Sever here... I understand the concept of joining tables, etc. but what is the easiest way to determine which columns are shared?

Say for instance we ha

Answer 1

This could well indicate a fundamental design issue but to find column names shared by both tables a couple of options would be

SELECT name 
FROM sys.columns 
WHERE object_id IN (object_id('dbo.Table1'),
                    object_id('dbo.Table2'))
GROUP BY name
HAVING COUNT(*) = 2

Or

SELECT name 
FROM sys.columns 
WHERE object_id = object_id('dbo.Table1')
INTERSECT
SELECT name 
FROM sys.columns 
WHERE object_id = object_id('dbo.Table2')