MySQL ERROR 1005: Can't create table (errno: 150)

问题

I am trying to create the following table

 
 create table messaInScena
  (
    data               date,  
    ora                time,
    spazio             varchar(20),
    spettacolo         varchar(40),
    postiDisponibili   smallint,
    prezzoIntero       decimal(5,2),
    prezzoRidotto      decimal(5,2),
    prezzoStudenti     decimal(5,2),
    primary key (data, ora, spazio),
    foreign key (spazio) references spazio(nome) 
on update cascade on delete set null,
    foreign key (spettacolo) references spettacolo(titolo) 
on update cascade on delete set null,
    constraint RA3_1 check (postiDisponibili >= 0)     
  ) ;

but I get the following error: Error Code: 1005 Can not create table 'teatrosql.messainscena' (errno: 150)

The tables that are referenced by foreign keys are:

 
create table spazio
  (
    nome             varchar(20) primary key, 
    indirizzo        varchar(40) not null,
    pianta           varchar(20),
    capienza         smallint
  );

create table spettacolo
  (
    titolo             varchar(40) primary key,  
    descrizione        LONGBLOB,
    annoProduzione     char(4)
  );

I have already verified that the fk are unique and that there are no typos (but given a control also you that you never know :D). As you can see the reference fields are primary keys. between fields and fk reference types and dimensions coincide ..

where am I wrong??

the the other tables of DB

create table teatro
  (
    nome             varchar(20) primary key, 
    telefono         varchar(15),
    fax              varchar(15),
    indirizzo        varchar(40) not null,  
    email            varchar(30),
    url              varchar(30)
  );

create table biglietteria
  (
    nome             varchar(20) primary key, 
    indirizzo        varchar(40) not null,
    email            varchar(30),
    telefono         varchar(15),  
    teatro           varchar(20),
    foreign key (teatro) references teatro(nome) 
    on update cascade on delete set null
  );

create table orario
  (
    biglietteria     varchar(20), 
    giorno           varchar(10), 
    inizio           time, 
    fine             time, 
    primary key(biglietteria, giorno, inizio),
    foreign key (biglietteria) references biglietteria(nome)
    on update cascade on delete cascade
  );

create table notizia
  (
    data        date,
    ora         time,
    oggetto     varchar(100),
    testo       LONGBLOB,
    primary key(data, ora, oggetto)
  );

create table newsletter
  (
    teatro      varchar(20),
    data        date,
    ora         time,
    oggetto     varchar(100),
    primary key(teatro, data, ora, oggetto),
    foreign key (teatro) references teatro(nome)on update cascade on delete cascade,
    foreign key (data, ora, oggetto) references notizia(data, ora, oggetto) on update cascade on delete cascade
  );

create table dipendente
  (
    cf                     char(16) primary key, 
    nome                   varchar(20) not null, 
    cognome                varchar(20) not null,
    dataDiNascita          date,
    luogoDiNascita         varchar(20), 
    residenza              varchar(30), 
    telefonoFisso          varchar(15), 
    telefonoMobile         varchar(15),  
    email                  varchar(30)
  );

create table lavoro
  (
    teatro              varchar(20), 
    dipendente          char(16),
    dataAssunzione      date,
    ruolo               varchar(5),
    cda                 boolean,
    primary key(teatro, dipendente),
    foreign key (teatro) references teatro(nome) on update cascade on delete cascade,
    foreign key (dipendente) references dipendente(cf) on update cascade on delete cascade,
    constraint RA1 check (
    cda = false or 
    (year(current_date) - year(dataAssunzione) > 10) or
    (year(current_date) - year(dataAssunzione) = 10 and 
       month(current_date) > month(dataAssunzione)) or
    (year(current_date) - year(dataAssunzione) = 10 and 
       month(current_date) = month(dataAssunzione) and
       day(current_date) >= day(dataAssunzione)) 
    ),
      check (ruolo in ('CA', 'POD', 'CUSRP', 'ACF'))
  );

create table stipendio
  (
    dipendente    char(16), 
    inizio        date, 
    importo       decimal(6,2),
    primary key(dipendente, inizio),
    foreign key (dipendente) references dipendente(cf) on update cascade on delete cascade
  ) ;

create table luogo
  (
    teatro     varchar(20), 
    spazio     varchar(20),
    primary key(teatro, spazio),
    foreign key (teatro) references teatro(nome) on update cascade on delete cascade,
    foreign key (spazio) references spazio(nome) on update cascade on delete cascade
  ) ;

回答1:

You can check the status of InnoDB (SHOW ENGINE INNODB STATUS) to determine the exact reason why the constraints are failing. The other option is to add the foreign key constraints after creating the table.

In your case, it appears that you're missing the engine type. The column types must also match. The primary key's on the referenced tables are most likely NOT NULL, and they are not so in messaInScena.

create table spazio
  (
    nome             varchar(20) NOT NULL primary key, 
    indirizzo        varchar(40) not null,
    pianta           varchar(20),
    capienza         smallint
  ) ENGINE=InnoDB;

create table spettacolo
  (
    titolo             varchar(40) NOT NULL primary key,  
    descrizione        LONGBLOB,
    annoProduzione     char(4)
  ) ENGINE=InnoDB;

create table messaInScena
  (
    data               date,  
    ora                time,
    spazio             varchar(20) NOT NULL,
    spettacolo         varchar(40) NOT NULL,
    postiDisponibili   smallint,
    prezzoIntero       decimal(5,2),
    prezzoRidotto      decimal(5,2),
    prezzoStudenti     decimal(5,2),
    primary key (data, ora, spazio),
    foreign key (spazio) references spazio(nome) 
on update cascade on delete set null,
    foreign key (spettacolo) references spettacolo(titolo) 
on update cascade on delete set null,
    constraint RA3_1 check (postiDisponibili >= 0)     
  ) ENGINE=InnoDB;

回答2:

you are a genious! first of all I checked the status of InnoDB, and the reason of the proble was that i tried to set null the fk on delete so i changed the query in this way

create table messaInScena
  (
    data               date,  
    ora                time,
    spazio             varchar(20),
    spettacolo         varchar(40),
    postiDisponibili   smallint,
    prezzoIntero       decimal(5,2),
    prezzoRidotto      decimal(5,2),
    prezzoStudenti     decimal(5,2),
    primary key (data, ora, spazio),
    foreign key (spazio) references spazio(nome)
on update cascade on delete cascade,
    foreign key (spettacolo) references spettacolo(titolo) 
on update cascade on delete cascade,
    constraint RA3_1 check (postiDisponibili >= 0)     
  ) ;
  

and execute it. now it's work. anyway now I'll carry the changes that you suggest me

来源：https://stackoverflow.com/questions/17812616/mysql-error-1005-cant-create-table-errno-150