what is primary key,unique key, foreign key? can u teach me
in simple language?
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Answer Posted / kranthi
primary key: primary creates a clustered index on the
column and it doesn't allow null values.
unique key: unique key creates non clustered index by
default.it allows "one null value".
foreign key: A foreign key (FK) is a column or combination
of columns used to establish and enforce a link between the
data in two tables
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