Semi-complicated SQL query in PHP

[johnsmith153]

I have this kind of query:

 

SELECT db1.field, db2.field FROM table1 db1 INNER JOIN table2 db2 ON db1.matchingField=db2.matchingField INNER JOIN table3 db3 ON db2.matchingField=db3.matchingField

 

(table 3 is used as there are various other WHERE clauses etc.)

 

and need to add in so it pulls info from a 4th table

 

SELECT db1.field FROM table1 db1 UNION ALL SELECT db4.newField FROM table4

 

How would I merge the two queries?

 

 

[johnsmith153]

If this can't be done then please say and I'll have to look at some otyher way. Thanks.