How do you implement one-to-one, one-to-many and many-to- many relationships wh

How do you implement one-to-one, one-to-many and many-to-
many relationships while designing tables?

Question Posted / swapna

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How do you implement one-to-one, one-to-many and many-to- many relationships while designing tables..

Answer / swapna

One-to-One relationship can be implemented as a single
table and rarely as two tables with primary and foreign key
relationships.
One-to-Many relationships are implemented by splitting the
data into two tables with primary key and foreign key
relationships.
Many-to-Many relationships are implemented using a junction
table with the keys from both the tables forming the
composite primary key of the junction table.

It will be a good idea to read up a database designing
fundamentals text book.

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How do you implement one-to-one, one-to-many and many-to- many relationships while designing tables..

Answer / harish sharma

All relationships are implemented by primary key and
foreign keys.
One-to-one
When we use two tables to relate by one primary key in one
table and one foreign key in secound table.
for example Employee table and salary table.
One-to-many
When we use many table but primary key is only in one table
and in other tables we use foreign key to inter-relate
tables.
For example Emp_id(primary key) in Employee table is
assosiated with salary_emp_id (foreign key) in Salary table
and associated with tax_emp_id (foreign key) in
tax_collecation table and associated with pf_emp_id
(foreign key) in provident_fund table.
Many-to-many
When we use primary keys of two or more tables in a
saperate table and in this table we relate these with other
tables by foreign key and primary key

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How do you implement one-to-one, one-to-many and many-to- many relationships while designing tables..

Answer / sundar

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How do you implement one-to-one, one-to-many and many-to- many relationships while designing tables..

Answer / g2

Excellent!!! Swapna. Really good...

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