Have a look on employee table after bringing it in First Normal Form: EmpId To bring the employee Table in First Normal Form 1) Organize the ProjectId and ProjectName attribute values in single atomic values and then 2) EmpId and ProjectId attributes can uniquely identify each row of the employee table. To understand the concept of First Normal Form (1NF), consider this employee table for an example: EmpId A primary key or composite key can be used to uniquely identify records of the table. Each row of a table should have an unique identifier to uniquely identify the rows of the table i.e. no two rows of a table can be identical in 1NF.a cell (intersection of rows and columns) in a table must contain a single atomic value. All columns of a table must have a single atomic value in each row of a table i.e.Lets try to understand the types of normal form with an example of employee table: First Normal Form – 1NFĪ table can be in First Normal Form (1NF), when it satisfies below conditions: a table in 3NF must satisfy all conditions of 2NF which in turn must satisfy all conditions of 1NF. To qualify each normal form, a table must qualify the previous normal form conditions first i.e. Each normal form has some predefined standards which must be followed to qualify that normal form. During normalization process database designer converts the database tables in normal forms and check its functional dependency. Normal form defines a set of standard which must be followed for a good database design. Lets discuss what is a normal form in next sub section. A table must satisfy all conditions of that normal form to qualify be in that normal form. During normalization process, we have various normal forms with some conditions. It is easy to find and fix any design problem at this early stage. During normalization process, database designer decides the actual structure of the tables and their relationships. Decomposed tables are connected using relationships (primary keys and foreign keys) to reduce the insert, update and delete anomalies. This process increases the number of tables in the database but it minimizes the redundant (duplicate), inaccurate and inconsistent data in database. Normalization is a process of minimizing redundant data from database by decomposing the columns of a table into multiple tables. Lets start our discussion with definition of Normalization. In this chapter “Database normalization”, we are going to discuss database normalization process and normal forms. In previous chapter, “ Types of keys“, we had a good discussion on keys and their types in SQL Server.
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