SQL join with 3 4 tables creating multiple primary key columns

Question

I am trying to join 4 tables together, each with a column named Common Column , and another column containing numbers. Thus, when joined a table with 5 columns should be created, one Common Column column, and one columns from each of the 4 tables. However, the Common Column is being created with each join, so it shows up three times in the resulting dataset.

Code:

SELECT *
FROM `Table 1`
INNER JOIN `Table 2`
ON `Table 1`.`Common Column` = `Table 2`.`Common Column` 
INNER JOIN `Table 3`
ON `Table 3`.`Common Column` = `Table 2`.`Common Column` 
INNER JOIN `Table 4`
ON `Table 4`.`Common Column` = `Table 3`.`Common Column`;

Expected Output

Actual Output

EDIT:

When I use

SELECT `Common Column`, num1, num2, num3, num4 

as my first line, I get the following error:

Error Code: 1052. Column `Common Column` in field list is ambiguous

Answer 1

If you join using the USING syntax, the common column will only appear once:

SELECT *
FROM `Table 1`
INNER JOIN `Table 2` USING (`Common Column`)
INNER JOIN `Table 3` USING (`Common Column`)
INNER JOIN `Table 4` USING (`Common Column`);

That said, do avoid using select * ; it is always better to explicitly list the columns you want (qualifying them with table if needed). If you do

SELECT `Table 1`.`Common Column`, num1, num2, num3, num4 

then it doesn't matter how you join.