mysql> CREATE TABLE tbl_Test1(
    ->   ID INT,
    ->   Phone VARCHAR(35));
Query OK, 0 rows affected (0.01 sec)

mysql>   
mysql> CREATE TABLE tbl_Test2(
    ->   ID INT,
    ->   Vorname VARCHAR(36),
    ->   PhoneLike VARCHAR(29));
Query OK, 0 rows affected (0.00 sec)

mysql> insert into tbl_Test1 values(1,123456);
Query OK, 1 row affected (0.00 sec)

mysql> insert into tbl_Test1 values(2,7235);
Query OK, 1 row affected (0.00 sec)

mysql> insert into tbl_Test2 values(1,'Teutales',1234);
Query OK, 1 row affected (0.00 sec)

mysql> select * FROM tbl_Test1, tbl_Test2 WHERE tbl_Test1.Phone like CONCAT(tbl_Test2.PhoneLike,'%');
+------+--------+------+----------+-----------+
| ID   | Phone  | ID   | Vorname  | PhoneLike |
+------+--------+------+----------+-----------+
|    1 | 123456 |    1 | Teutales | 1234      |
+------+--------+------+----------+-----------+
1 row in set (0.00 sec)