what is the difference between primary key & foreign key?

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what is the difference between primary key & foreign key?..

Answer / vij&pani

Primary key is unique key but foriegn key always refers to
primary key

Is This Answer Correct ?    327 Yes 50 No

what is the difference between primary key & foreign key?..

Answer / ramprakash

Primary keys enforce entity integrity by uniquely
identifying entity instances. Foreign keys enforce
referential integrity by completing an association between
two entities.

Is This Answer Correct ?    275 Yes 50 No

what is the difference between primary key & foreign key?..

Answer / guest

Primary key is unique
primary key is not NULL and

foreign key is NULL
foreign key reference as Primary key in another table

Is This Answer Correct ?    250 Yes 62 No

what is the difference between primary key & foreign key?..

Answer / guest

primary key is used to identify a row and it doesnot allow
null values. It avoids duplication of rows.

whereas foreign key refers to a column or combination of
columns included in the defenition of referential integrity.

Is This Answer Correct ?    155 Yes 19 No

what is the difference between primary key & foreign key?..

Answer / muneer

Primary Key is unique Key entire the table and which is
also NOT NULL
where as foriegn key is the null & which references the
primary key .

Is This Answer Correct ?    147 Yes 28 No

what is the difference between primary key & foreign key?..

Answer / shaik gouse peer

Basic difference betweeen Primary key and foreign key is :

Primary key will not allow "Null values" and "Duplicate
values"

Foreign key will allow "Null values" and "Duplicte values"
and it refers to a primary key in anoter table.

Is This Answer Correct ?    130 Yes 25 No

what is the difference between primary key & foreign key?..

Answer / guest

primary key is the parent and foreign is the child.

Is This Answer Correct ?    132 Yes 73 No

what is the difference between primary key & foreign key?..

Answer / hardik patel

primary key is used to identify a row and it doesnot allow
null values. It avoids duplication of rows.

whereas foreign key refers to a column or combination of
columns included in the defenition of referential integrity.

Is This Answer Correct ?    65 Yes 20 No

what is the difference between primary key & foreign key?..

Answer / gaurav , ashish ,preeti , main

Primary key is used to identify a row in a table and it
doesnot allow null values. It avoids duplication of rows.

whereas foreign key refers to a column or combination of
columns included in the defenition of referential integrity

Is This Answer Correct ?    57 Yes 16 No

what is the difference between primary key & foreign key?..

Answer / raghu

In the context of relational databases, a foreign key is a
referential constraint between two tables.[1] The foreign
key identifies a column or a set of columns in one
(referencing) table that refers to a column or set of
columns in another (referenced) table. The columns in the
referencing table must form a primary key or unique key.

Is This Answer Correct ?    58 Yes 20 No

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