How can I do an UPDATE statement with JOIN in SQL Server?

Question

I need to update this table in SQL Server with data from its \'parent\' table, see below:

Table: sale

id (int)
udid         


        

Answer 1

Teradata Aster offers another interesting way how to achieve the goal:

MERGE INTO ud --what trable should be updated
USING sale -- from what table/relation update info should be taken
ON ud.id = sale.udid --join condition
WHEN MATCHED THEN 
    UPDATE SET ud.assid = sale.assid; -- how to update

Answer 2

The simplest way is to use the Common Table Expression (CTE) introduced in SQL 2005

with cte as
(select u.assid col1 ,s.assid col2 from ud u inner join sale s on u.id = s.udid)
update cte set col1=col2

Answer 3

Try this one, I think this will works for you

update ud

set ud.assid = sale.assid

from ud 

Inner join sale on ud.id = sale.udid

where sale.udid is not null

Answer 4

Simplified update query using JOIN-ing multiple tables.

   UPDATE
        first_table ft
        JOIN second_table st ON st.some_id = ft.some_id
        JOIN third_table tt  ON tt.some_id = st.some_id
        .....
    SET
        ft.some_column = some_value
    WHERE ft.some_column = 123456 AND st.some_column = 123456

Note - first_table, second_table, third_table and some_column like 123456 are demo table names, column names and ids. Replace them with the valid names.

Answer 5

Another example why SQL isn't really portable.

For MySQL it would be:

update ud, sale
set ud.assid = sale.assid
where sale.udid = ud.id;

For more info read multiple table update: http://dev.mysql.com/doc/refman/5.0/en/update.html

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

Answer 6

This should work in SQL Server:

update ud 
set assid = sale.assid
from sale
where sale.udid = id