To change data of an already created table UPDATE is used. The UPDATE statement combined with JOIN can update a TABLE with the records of other table. JOIN such as INNER JOIN, LEFT/RIGHT JOIN, or SIMPLE JOIN can work individually or in conjunction with UPDATE.

UPDATE table 

SET Col_Name1 = table2.Col_Name1, 

Col_Name2 = table2.Col_Name2?.. 

FROM Table1 t1 

INNER JOIN table2 t2 ON table1.Col_Name1 = t2.Col_Name1 

WHERE Condition for Join; 

In this example there are two tables with columns Col_Name1 of table 1 and Col_Name2 of table 2 having same values. To update table1 with values of table2 where Col_Name1 values are greater than 100, SET the other columns of table2 and JOIN table2 with table1 ON Col_Name1, WHERE values of Col_Name1 are greater than 100.

UPDATE Table1 

INNER JOIN Table2 ON Table1.Col_Name1 = Table2.Col_Name1 

SET Col_Name2 = Table2.Col_Name2, 

Col_Name3 = Table2.Col_Name3 

WHERE Col_Name1 > 100;