#1072 - Key column 'Customer_ID' doesn't exist in table - mysql

Question

This is the parent table
CREATE TABLE Customer(
Customer_ID INT(5) not null,
CustName VARCHAR(50) not null,
CustSurname VARCHAR(50) not null,
CustEmail VARCHAR(100) unique not null,
CustMobileNo INT(12) not null,
HomeAddress VARCHAR(255) not null,
Password VARCHAR(10) not null,
constraint c_cuid_pk PRIMARY KEY (Customer_ID))
ENGINE = InnoDB;
When I try to create the property table it shows me
"#1072 - Key column 'Customer_ID' doesn't exist in table"
this is the child table
CREATE TABLE Property(
Property_ID INT(5) not null,
PhouseNumber INT(4) not null,
PstreetName VARCHAR(50) not null,
PpostCode VARCHAR(7) not null,
Pcity VARCHAR(20) not null,
constraint p_phn_pk PRIMARY KEY (Property_ID),
constraint p_cuid_fk FOREIGN KEY (Customer_ID)
references IndividualCustomer(Customer_ID))
ENGINE = InnoDB;

Answer 1

In table Property, you must define a column named Customer_ID (well it could be named anything!), then you define the FOREIGN KEY on it.
Your code currently tries to link IndificualCustomer(Customer_ID) to Property(Customer_ID), but Property(Customer_ID) does not exist.
Declaring the constraint just links the columns, but it does not create them.
CREATE TABLE Property(
Property_ID INT(5) not null,
PhouseNumber INT(4) not null,
PstreetName VARCHAR(50) not null,
PpostCode VARCHAR(7) not null,
Pcity VARCHAR(20) not null,
Customer_ID INT(5) not null,
constraint p_phn_pk PRIMARY KEY (Property_ID),
constraint p_cuid_fk FOREIGN KEY (Customer_ID)
references IndividualCustomer(Customer_ID))
ENGINE = InnoDB;

Answer 2

In the first place, you should add a column: Customer_ID to your Property table to create your foreign key constraint:
Property.Customer_ID →　IndividualCustomer.Customer_ID
You can not make a constraint on something that does not exist.
Or change the +++ +++ part of your table creation query to a column that exists.
constraint p_cuid_fk FOREIGN KEY (+++Customer_ID+++) --to be changed accordingly
references IndividualCustomer(Customer_ID)
Example: adding the Customer_ID column to your table declaration would give you the following code
CREATE TABLE Property(
Property_ID INT(5) not null,
Customer_ID INT(5) not null,
PhouseNumber INT(4) not null,
PstreetName VARCHAR(50) not null,
PpostCode VARCHAR(7) not null,
Pcity VARCHAR(20) not null,
constraint p_phn_pk PRIMARY KEY (Property_ID),
constraint p_cuid_fk FOREIGN KEY (Customer_ID)
references IndividualCustomer(Customer_ID))
ENGINE = InnoDB;

Answer 3

CREATE TABLE Property(
Property_ID INT(5) not null,
PhouseNumber INT(4) not null,
PstreetName VARCHAR(50) not null,
PpostCode VARCHAR(7) not null,
Pcity VARCHAR(20) not null,
Customer_ID INT(5) not null,
PRIMARY KEY (Property_ID),
KEY p_cuid_fk (Customer_ID),
constraint p_cuid_fk FOREIGN KEY (Customer_ID)
references Customer(Customer_ID))
ENGINE = InnoDB;
You have to add Customer_ID in the table PROPERTY.