Relational Data Model Assignment Example | Topics and Well Written Essays - 1000 words

Relational Data Model - Assignment Example The attribute "is leader" should be removed from the table Candidate because this information already exists in the table Party. It is possible to get to know if a Candidate is leader of any party with looking through references to leaders in the table Party. .. First_name Middle_name Last_name address gender date of birth Party Pk_id Fk_leader name address date established Candidate Pk_id Fk_electorate Fk_party First_name Middle_name Last_name address gender date of birth is leader Second normal form (2NF) further addresses the concept of removing duplicative data: Meet all the requirements of the first normal form. Remove subsets of data that apply to multiple rows of a table and place them in separate tables. Create relationships between these new tables and their predecessors through the use of foreign keys. (Chapple 2005) So, personal information, such as name (first, middle, last), address, gender, and date of birth can be taken apart into separate table Person. It also should have a primary key named Pk_id. Then tables Elector and Candidate should reference to it via secondary (foreign) key Fk_person. Therefore there are 5 tables in the relational database schema for the 2NF: Person Pk_id First_name Middle_name Last_name address gender date of birth Electorate Pk_id unique name number of registered voters Elector Pk_id Fk_electorate Fk_party_vote Fk_candidate_vote Fk_person Party Pk_id Fk_leader name address date established Candidate Pk_id Fk_electorate Fk_party Fk_person is leader Third normal form (3NF) goes one large step further: Meet all the requirements of the second normal form. Remove columns that are not dependent upon the primary key. (Chapple 2005) The attribute "is leader" should be removed from the table Candidate because this information already exists in the table Party. It is possible to get to know if a Candidate is leader of any party with looking through references to leaders in the table Party. There's no attributes that are not dependent upon the primary key. Here are

Theory Research Essay Example | Topics and Well Written Essays - 750 words

Theory Research - Essay Example e research the social organisation theory and previous research that have been undertaken with regard to this theory, theories related to the social disorganisation discussed in this paper include the gang theory, the concentric zone theory, the cultural transmission theory and the differential social organisation concept. The Social disorganisation theory depicts that crime occurs as a result of failure by the society to organise its institutions, Assumptions of the social disorganisation theory on crime are that crime is caused by social factors, individuals in the society are unable to resist temptation and that the social structure in the society is unstable, according to the assumptions when crime occurs people blame the perpetrators and don’t blame on social disorganisation in the society, for this reason therefore it is almost impossible to identify the causes of crime. Robert Sampton (1997) developed the collective efficacy and social capital concepts, according to him collective efficacy referred to the maintenance of order in the society while social capital referred to the informal networks ties that exist in a society. He stated that a society must first achieve social capital in order to achieve collective efficacy, for this reason therefore he supported the social disorganisation theory by stating that modern societies lack social capital and therefore has not achieved social efficacy and this explains the existence of crime. The gang theory is also another theory that explains social disorganisation in the society. In this theory the various characteristics of gang behaviour include solidarity, shared traditions and cooperation. The theory depicts that gang’s start as groups and collected in certain areas of a society especially area between developed areas, for this reason the presence of gangs can explain the existence of high crime rates in certain regions. The concentric zone theory also explain the existence of crime due to social