MYSQL - #1005 - Can't create table 'dbwms.t_trucks' (errno: 150)

Question

I am new to mysql and have the enclosed code to generate the database & tables. The first 2 tables are generated fine, but I get the above error (in subject line). Can you please help.

CREATE DATABASE IF NOT EXISTS dbwms DEFAULT CHARACTER SET `utf8`;

USE dbwms;

CREATE TABLE IF NOT EXISTS t_truck_types (
f_pk_ma_truck_type SMALLINT NOT NULL AUTO_INCREMENT PRIMARY KEY,
f_sa_truck_type CHAR(4) NOT NULL UNIQUE, INDEX(f_sa_truck_type),
f_truck_length TINYINT
) ENGINE=InnoDB DEFAULT CHARACTER SET `utf8`;

CREATE TABLE IF NOT EXISTS t_truck_vendors (
f_pk_ma_truck_vendor_id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
f_sa_truck_vendor_id SMALLINT UNSIGNED NOT NULL UNIQUE, INDEX(f_sa_truck_vendor_id),    
f_truck_vendor_nickname VARCHAR(12) NOT NULL UNIQUE, INDEX(f_truck_vendor_nickname)
) ENGINE=InnoDB DEFAULT CHARACTER SET `utf8`;

CREATE TABLE IF NOT EXISTS t_trucks (
f_pk_ma_truck_id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
f_truck_license_plate VARCHAR(15) NOT NULL UNIQUE, INDEX(f_truck_license_plate),
f_fk_ma_truck_type SMALLINT UNSIGNED NOT NULL,
f_fk_ma_truck_vendor_id SMALLINT UNSIGNED NOT NULL,
FOREIGN KEY (f_fk_ma_truck_type) REFERENCES t_truck_types(f_pk_ma_truck_type),
FOREIGN KEY (f_fk_ma_truck_vendor_id) REFERENCES t_truck_vendors(f_pk_ma_truck_vendor_id)
) ENGINE=InnoDB DEFAULT CHARACTER SET `utf8`;

Thanks in advance for your help.

sbeeht

Answer 1

That's because f_fk_ma_truck_type in t_trucks defined as an UNSIGNED. Both primary key and the foreign key should be of the same type. You may removed unsigned in t_trucks

CREATE TABLE IF NOT EXISTS t_trucks (
f_pk_ma_truck_id SMALLINT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
f_truck_license_plate VARCHAR(15) NOT NULL UNIQUE, INDEX(f_truck_license_plate),
f_fk_ma_truck_type SMALLINT NOT NULL,
f_fk_ma_truck_vendor_id SMALLINT UNSIGNED NOT NULL,
FOREIGN KEY (f_fk_ma_truck_type) REFERENCES t_truck_types(f_pk_ma_truck_type),
FOREIGN KEY (f_fk_ma_truck_vendor_id) REFERENCES t_truck_vendors(f_pk_ma_truck_vendor_id)
) ENGINE=InnoDB DEFAULT CHARACTER SET `utf8`;

or add it in the t_truck_types declaration