Table 1 and Table 2 have matching columns. How do I join the 9th column from table 2 to table 1 based on the matches? My Issue: 

I want to know if an account has an active error.


Background Information:

I have 2 tables: 
    (1) Work - 9 Columns; 
    (2) Errors - 9 Columns

The Work table contains Account Numbers and 8 variables which are associated to an error from the Errors table.

The Errors table contains each possible error. Each error has 8 variables and is either set as on (y) or off (n) with an Active Flag column.

    In table 1 (Work) I have 9 columns:
    (i) acct_number
    (ii) system
    (iii) source
    (iv) object
    (v) group
    (vi) code
    (vii) detail
    (viii) routing
    (ix) complexity

    In Table 2 (Errors) I have 9 Columns:
    (i) active_flag
    (ii) system
    (iii) source
    (iv) object
    (v) group
    (vi) code
    (vii) detail
    (viii) routing
    (ix) complexity


Therefore both tables have the same columns except that the Error table does not have the acct_number column and the Work table does not have the active_flag column. 

I am attempting to match (join) the active_flag column from the Error table to the Work table based on a match from the other 8 columns.

The result I am looking would look like this: acct_number, active_flag (where each account number is showing whether or not the error associated is active or inactive).
SELECT *
FROM tbl1
JOIN tbl2
  USING (
    acct_number,
    system,
    source,
    object,
    group,
    code,
    detail,
    routing,
    complexity
  );


But this is insanity. You should be reducing this to a sane primary key. Even if you're primary key is a natural key, this many columns is highly indicative of bad practice.