Normalization is the most important concept for designing SQL. To normalize data on database we follow some rules called normalization rules.
There some rules for normalization.
Rule 1: There should be a one-to-one relationship between the instances of an entity and the rows of the table.
Rule 2 : A field should have the same meaning in each row of the table.
Rule 3 : Each table should represent at most one entity.
Rule 4 : Multiple instances of an entity should be represented by multiple rows in a table.
Rule 4.1: Multiple instances of an entity should not be represented as multiple columns.
Rule 4.2: Multiple instances of an entity should not be represented as multiple tables.
Rule 5 :Joins should be based only on primary and foreign-key equality.
Rule 6 :Make sure keys are linked correctly.
There some rules for normalization.
Rule 1: There should be a one-to-one relationship between the instances of an entity and the rows of the table.
Rule 2 : A field should have the same meaning in each row of the table.
Rule 3 : Each table should represent at most one entity.
Rule 4 : Multiple instances of an entity should be represented by multiple rows in a table.
Rule 4.1: Multiple instances of an entity should not be represented as multiple columns.
Rule 4.2: Multiple instances of an entity should not be represented as multiple tables.
Rule 5 :Joins should be based only on primary and foreign-key equality.
Rule 6 :Make sure keys are linked correctly.
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