sql update a column with value from another column code example

Example 1: sql server update column based on another table

UPDATE
    Sales_Import
SET
    Sales_Import.AccountNumber = RAN.AccountNumber
FROM
    Sales_Import SI
INNER JOIN
    RetrieveAccountNumber RAN
ON 
    SI.LeadID = RAN.LeadID;

Example 2: sql update with field from another table

UPDATE table1 
   SET price=(SELECT price FROM table2 WHERE table1.id=table2.id);