mySql多列连接与重合数据

Question

I have three tables. Each one has three columns. It looks like this:

table 1                   table 2                    table 3
--------------------      --------------------       --------------------
col1    col2    colA      col1    col2    colB       col1    col2    colC
1       A       data      3       C       data       5       E       data
2       B       data      2       B       data       6       F       data
3       C       data      1       A       data       3       C       data
4       D       data      4       D       data       2       B       data
5       E       data      6       F       data       1       A       data
6       F       data      5       E       data       3       C       data

My question is if it is at all possible with JOINS to output something like this:

output table                
-----------------------------------------
col1    col2    colA       colB      colC
1       A       data       data      data
2       B       data       data      data
3       C       data       data      data
4       D       data       data      data
5       E       data       data      data
6       F       data       data      data

Note that Col1 and Col2 always have the same values in the different columns but are in different order.

I don't even know if this is possible but ideally the query would join the three tables and relate the information on col1 and col2 with each respective table and reorder the two joining tables and output a single table/array.

Let me know if this is really stupid or complex... I've been trying to wrap my head around this but by mySql knowledge is very limited.

Answer 1

SELECT *
FROM t1
LEFT JOIN t2 USING (col1, col2)
LEFT JOIN t3 USING (col1, col2)