update relation question

[chucklarge]

hello,
it makes sense now to change some table schemes and remove some of the relations.
i have a 'users' table with an id and a username. a second table has a user_id field with the user id. i have created a field in the second table called username and want to update the table with the username.

for example
-users-
id username
1 john
2 bill
3 doug
4 larry
5 chris

-sales-
user_id username
4
4
4
2
3
3
4
4
1
5

so i would want to create this
-sales-
user_id username
4 larry
4 larry
4 larry
2 bill
3 doug
3 doug
4 larry
4 larry
1 john
5 chris

how can i do this with sql?

thanks,
chuck

[bogu]

mysql_manual wrote:

UPDATE Multiple-table syntax:

UPDATE [LOW_PRIORITY] [IGNORE] table_references
SET col_name1=expr1 [, col_name2=expr2 ...]
[WHERE where_condition]

click here to read more about UPDATE SYNTAX.