What is the difference between the Primary and Foreign key?
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Answer Posted / suresh babu
Primary key and foreign key both are constraints.
Primary key:We can create only one primary key for a
table,which never allows the repeated or duplicate values
and null values.The index will be created when defining a
primary key.And primary key is used to make a relation
between more than one tables.
Foreign key:It allows the duplicate and null values.if we
want to make a relation between two tables,the parent table
column must have primary column and child table column
called foreign key.
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