SQL insert data with inner join using oracle

Question

New to SQL I have two tables table_A and table_B.

I want to add data into a specific column of table_A depending on a inner join on table_B. I am using Oracle, following this method my SQL looks like this :

I first tried that :

INSERT INTO table_A (target_column)
SELECT table_B.wanted_data 
FROM table_B INNER JOIN table_A ON table_B.someColumnB = table_A.someColumnA

Here the issue is that it would insert the data in new lines of my table_A and not in the existing lines.

So I tried that from the stackoverflow thread :

UPDATE(SELECT table_A.target_column, table_B.wanted_data
  FROM table_A
  INNER JOIN table_B
  ON table_A.someColumnA = table_B.someColumnB
)
SET table_A.target_table = table_B.wanted_data

But it is not working either "SQL command not properly ended"

EDIT : target_column and wanted_data have the same name in my data set, not sure if it changes anything.

Answer 1

SQL Sever:

UPDATE a 
SET    a.target_column = b.wanted_data 
FROM   table_A a 
JOIN   table_B b 
ON     b.someColumnB = a.someColumnA

Oracle:

UPDATE
(
    SELECT     b.wanted_data   AS wanted_data
              ,a.target_column AS old_data
    FROM       table_A a
    INNER JOIN table_B b
    ON         b.someColumnB = a.someColumnA
)   c
SET c.old_data = c.wanted_data