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What is the primary key for the properties table?
Primary key is to set property ID as the primary key for the properties table.
How do you define a primary key in MS Access?
A primary key is a field or set of fields with values that are unique throughout a table. Values of the key can be used to refer to entire records, because each record has a different value for the key.
Why must the primary key of a parent table be determined before the foreign key in the child table?
Because the foreign key is copied from the primary key of the parent table
Is it necessarily that a foreign key is primary key in other table?
It is not mandatory that is must be a primary key but it must be a unique key in the other table.
What does the term foreign key mean in databases?
A foreign key is a field in a database table that is used to establish a relationship with another table. It ensures referential integrity by enforcing a link between two tables based on a matching key. This key is typically a primary key in the referenced table.
Can a primary key be a foreign key?
Yes, a primary key can also be a foreign key. This is known as a composite key, where one or more columns in a table are both primary keys for that table and also act as foreign keys linking to another table.
How a primary key is fixed in a sql table?
A primary key field in a sql table is created using the PRIMARY KEY keyword. ex: CREATE TABLE tbl_employee ( emp_num VARCHAR(10), emp_name VARCHAR(100), PRIMARY KEY (emp_num)) The above script creates a table called tbl_employee and sets the emp_num field as the primary key
Can a column in a composite key be a foreign key to another table?
Hi, As per I know you can't define a foreign key column which is a part of a composite primary key of another table. Only way you've to refer all the columns of that composite key. UKD
Can super key be as primary key?
I think super key is treated as the primary key because in a table their will be only one primary key.
What is primery key?
primary key is a column or set of columns (called composite primary key ) that identify the table & make every table unique .value of a primary key can not duplicated & can not be NULL .
How do you create a primay key in Oracle?
You can create a primary key column in an oracle table using the PRIMARY KEY keyword. Assuming you have an employee table that has employee information and has a column called emp_num. you can create a primary key in the table using the below command. ALTER TABLE tbl_employee_info add CONSTRAINT emp_pk PRIMARY KEY (emp_num) If you execute the above command in your database, emp_num will become the primary key of the table tbl_employee_info.
What is a primary key what is its purpose and why do you use it?
What is a Primary Key?The PRIMARY KEY constraint uniquely identifies each record in a database table.Primary keys must contain unique values.A primary key column cannot contain NULL values.Each table should have a primary key, and each table can have only ONE primary key.The primary key is defined by using the PRIMARY KEY constraint when either creating a table or altering a table.*Example of primary key :- customer Nowhat is its purpose and why do you use it?In relational database design, a unique key or primary key is a candidate key to uniquely identify each row in a table.
