spambot

/* Intersecção em MySql com INNER JOIN */



/* Criando banco de exemplo */



CREATE DATABASE teste;



USE teste;



/* Criando tabelas de exemplo */



CREATE TABLE tabela1 (

	id INT(11) PRIMARY KEY

);



CREATE TABLE tabela2 (

	id INT(11) PRIMARY KEY

);



CREATE TABLE tabela3  (

	id INT(11) PRIMARY KEY

);



INSERT INTO tabela1 VALUES (1);

INSERT INTO tabela1 VALUES (2);

INSERT INTO tabela1 VALUES (3);



INSERT INTO tabela2 VALUES (2);

INSERT INTO tabela2 VALUES (3);

INSERT INTO tabela2 VALUES (4);



INSERT INTO tabela3 VALUES(3);

INSERT INTO tabela3 VALUES(4);

INSERT INTO tabela3 VALUES(5);



/* Assim temos estas tabelas: */

/*

tabela1

+----+

| id |

+----+

|  1 |

|  2 |

|  3 |

+----+



tabela2

+----+

| id |

+----+

|  2 |

|  3 |

|  4 |

+----+



tabela3

+----+

| id |

+----+

|  3 |

|  4 |

|  5 |

+----+

*/



SELECT

	a.id

FROM tabela1 a

	INNER JOIN tabela2 b ON (a.id = b.id)

	INNER JOIN tabela3 c ON (a.id = c.id)

ORDER BY a.id



/*

+----+

| id |

+----+

|  3 |

+----+

*/