SQL - consulta sql ¿necesario cursores?

mysql> SELECT * FROM tabla;

+------+------+-------+--------+

| id   | tipo | linea | nombre |

+------+------+-------+--------+

|    1 | a    |     2 | juan   |

|    2 | b    |     1 | pepe   |

|    2 | b    |     4 | pepito |

|    3 | b    |     1 | pepote |

+------+------+-------+--------+

4 rows in set (0.00 sec)

mysql> SELECT id, MIN(linea) min_linea

    -> FROM tabla

    -> where tipo  = 'b'

    -> GROUP BY id;

+------+-----------+

| id   | min_linea |

+------+-----------+

|    2 |         1 |

|    3 |         1 |

+------+-----------+

2 rows in set (0.00 sec)

mysql> SELECT T1.*

    -> FROM tabla T1

    -> INNER JOIN

    -> ( SELECT id, MIN(linea) min_linea

    ->   FROM tabla

    ->   where tipo  = 'b'

    ->   GROUP BY id) T2 on T2.id = T1.id and T2.min_linea = T1.linea;

+------+------+-------+--------+

| id   | tipo | linea | nombre |

+------+------+-------+--------+

|    2 | b    |     1 | pepe   |

|    3 | b    |     1 | pepote |

+------+------+-------+--------+

2 rows in set (0.00 sec)

De acuerdo, pero hay algo que no entiendo o no se hacer ¿Como puedo crear las tablas para hacer

un inner join?