What is the difference between a foreign key and a primary foreign key?
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I understand that you use foreign keys to relate rows from one table to the other and if this foreign key also becomes a primary key of that table then it is a primary foreign key.
But, for example, if a hotel records the date and time of check-ins for each customer, and each customer has a customer ID, should I include the customer ID as a primary foreign key or just a foreign key? Because at one time there can be multiple check-ins so date and time is not enough as a primary key?
database-design foreign-key primary-key uniqueidentifier
asked 8 mins ago
Sook LimSook Lim
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I understand that you use foreign keys to relate rows from one table to the other and if this foreign key also becomes a primary key of that table then it is a primary foreign key.
But, for example, if a hotel records the date and time of check-ins for each customer, and each customer has a customer ID, should I include the customer ID as a primary foreign key or just a foreign key? Because at one time there can be multiple check-ins so date and time is not enough as a primary key?
database-design foreign-key primary-key uniqueidentifier
asked 8 mins ago
Sook LimSook Lim
81
New contributor
Sook Lim is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I understand that you use foreign keys to relate rows from one table to the other and if this foreign key also becomes a primary key of that table then it is a primary foreign key.
But, for example, if a hotel records the date and time of check-ins for each customer, and each customer has a customer ID, should I include the customer ID as a primary foreign key or just a foreign key? Because at one time there can be multiple check-ins so date and time is not enough as a primary key?
database-design foreign-key primary-key uniqueidentifier
asked 8 mins ago
Sook LimSook Lim
81
New contributor
Sook Lim is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I understand that you use foreign keys to relate rows from one table to the other and if this foreign key also becomes a primary key of that table then it is a primary foreign key.
But, for example, if a hotel records the date and time of check-ins for each customer, and each customer has a customer ID, should I include the customer ID as a primary foreign key or just a foreign key? Because at one time there can be multiple check-ins so date and time is not enough as a primary key?
database-design foreign-key primary-key uniqueidentifier
database-design foreign-key primary-key uniqueidentifier
asked 8 mins ago
Sook LimSook Lim
81
New contributor
Sook Lim is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 8 mins ago
Sook LimSook Lim
81
New contributor
Sook Lim is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 8 mins ago
Sook LimSook Lim
81
New contributor
Sook Lim is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 8 mins ago
Sook LimSook Lim
81
asked 8 mins ago
Sook LimSook Lim
81
81
New contributor
Sook Lim is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Sook Lim is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Sook Lim is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
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