I need help structuring an UPDATE statement with multiple joins

Okay I have an application where I need to replace a variable in one data table with the value from another data table. Problem is there are two table in between that relates the records and I can’t figure out how to structure the update statement.

I use a join like the one below to return a record set.

SELECT Table_1.Var_1, Table_1.Var_2, Table_2.Var_3, Table_2.Var_4, Table_2.Var_5, Table_3.Var_6, Table_3.Var_7, Table_3.Var_8, Table_4.Var_9, Table_4.Var_10 FROM Table_1, Table_2, Table_3, Table_4 WHERE Table_1.Var_2 = Table_2.Var_3 AND Table_2.Var_4 = Table_3.Var_6 AND Table_2.Var_5 = Table_3.Var_7 AND Table_3.Var_8 = Table_4.Var_9

I need to then replace Var_1 in Table_1 with Var_10 from Table_4 for all of the records returned by the SELECT statement. The SELECT statement works perfectly. I’ve worked on the update for a while and sadly have made no significant headway. Any suggestions and help will be greatly appreciated.

Thank you!
iRead

update table_1
set var_1 =table_4.var_10
FROM Table_1, Table_2, Table_3, Table_4 WHERE Table_1.Var_2 = Table_2.Var_3 AND Table_2.Var_4 = Table_3.Var_6 AND Table_2.Var_5 = Table_3.Var_7 AND Table_3.Var_8 = Table_4.Var_9


Voila!