Question

Normalize the following data by:

a) identifying the functional dependencies,

b) stating your assumptions, \

c) creating relations, and

d) identifying primary and foreign keys.

Customer Number| First Name |Last Name |Phone | Invoice Number| Date |Item Type |Quantity Item Price

Answer 1

As the given data is

Customer Number| First Name |Last Name |Phone | Invoice Number| Date |Item Type |Quantity Item Price.

now the solutions are:

a) identifying the functional dependencies :

ans: a functional dependency is defined as the realtionship between the two attirbutes in a data, so generally this functional dependency will be created between the primary key and the non-key attribute.

so from the above given data then functional dependency will be the customer first name.
becuase here the primary key is the Customer Number and by using Customer number it is easy to find the customer first name. so customer first name is the functional dependency.

b) stating your assumptions

the assumptions are defined as the events which appears during a project start to end cyle process and they will throughly analysed. the assumption condition will always be true in the starting and it plays a key role in completing a project with less disturbances.

so from the given data the assumption will helps in creating the analysing the data perfectly.

c) creating relations,

generally the relations are defined as representing a parituclar data with a specific character. now in sql tables relations are defined as the tables where a table is considered as single tuple and the values in each attribute will be considered as a column.

so from the given above data the whole table will be considered as single tuple.

d) identiying the primary key and foriegn key

primary key is defined as the key where it is used as a unique identifer to retrieve the data.
the features of primary key are:
1. it has a unique value
2. it should not contain null values.
3. there should be only one primary key in a table.

so from the above given table the primary key is Customer Number

foreign key is defined as the key which is used as a link between the tables. the foriegn key in one table is used to match the primary key in another table.

so from the above given data the foriegn key is Invoice number.