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what is primary key,unique key, foreign key? can u teach me
in simple language?
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Answer Posted / inderjeet yadav
Primary key:A key which is uniquely indetified a row in a
table and primary key can not be null.
Unique key: A key which is uniquely indetified a row in a
table and but unique key can be null.
Foreign:Primary key of the first table that refering in
second table is know as foreign of second table.
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