SQL statement: how can I pick a value only once from a table to update another table?

I wish to update table1 with any distinct value of table2 matching the same code, no matter which one or the order (value from table2 can’t be picked more than once)

+-------------------+      +--------------+
|      table1       |      |    table2    |
+-------------------+      +--------------+
| id | code | value |      | code | value |
+----+------+-------+      +------+-------+
| 1  |  A   |       | <--  |  A   |  v1   |
| 2  |  A   |       |      |  B   |  v2   |
| 3  |  B   |       |      |  A   |  v3   |
+----+------+-------+      |  A   |  v5   |
                           |  A   |  v6   |
                           +------+-------+
+-------------------+                      
|      table1       |                      
+-------------------+                      
| id | code | value |
+----+------+-------+
| 1  |  A   |  v6   |
| 2  |  A   |  v3   |
| 3  |  B   |  v2   |
+----+------+-------+

How can I write the SQL update statement ? (MySQL 5.7)

Answer

The statement provided by Madhur Bhaiya does work if

1. @rn* are initialized to 1 instead of 0 (otherwise row_num* are numbered 1 twice)
2. the SELECT from table2 is DISTINCT (because pairs of (code,value) are repeated in table2)

The statement should be

UPDATE 
table1 AS t1 

JOIN 

(SELECT 
   dt1.id, 
   IF(@cd1 = dt1.code, @rn1 := @rn1 + 1, 1) AS row_num1, 
   @cd1 := dt1.code AS code,
 FROM (SELECT id, code FROM table1 ORDER BY code, id) AS dt1
 CROSS JOIN (SELECT @rn1 := 1, @cd1 := '') AS init1
) AS t2 
  ON t2.id = t1.id 

JOIN 

(SELECT 
   IF(@cd2 = dt2.code, @rn2 := @rn2 + 1, 1) AS row_num2, 
   @cd2 := dt2.code AS code, 
   dt2.value 
 FROM (SELECT DISTINCT code, value FROM table2 ORDER BY code) AS dt2
 CROSS JOIN (SELECT @rn2 := 1, @cd2 := '') AS init2
) AS t3 
  ON t3.row_num2 = t2.row_num1 AND 
     t3.code = t2.code 

SET t1.value = t3.value