ACF5904 AIS Tutorial 4

What we learnt so far in terms of system thinking skills development? Translate to BPMN language BPMN Models Given Case Study Texts Translate to Logical Data Model Using UML UML Data Models Translate to Physical Data Model Using MS Access ER Language MS Access ER Data Models Populate the MS Access Data Base with imported Excel tables MS Access Database Using MS Access Query Language to extract reports from the database MS Access Query Results

MS Access Query Language https://www.techopedia.com/definition/3948/query-language

2 ways of constructing MS Access Queries Using the Query Language itself Using the Query Wizard which guides you to construct short phrases to complete a query statement. Did you review https://www.gcflearnfree.org/access2016/designing-a-simple-query/1/ ?

More Complex Query Constructs Construct Query Statement Query Results They are also data files or tables Combine with other Query Results or MS Access Database Tables Complex Query Results

Query Wizard Prompts: What do they mean? Table Views: Select the data files/tables you intend to use to develop the query statement. The data files can also be saved queries, not just database tables Field : Ask you which fields (column by column) you want to include in data manipulation Table : where each stated fields are sourced from Sort – which stated field you want to sort Show – which stated field you want to display Criteria – what data manipulation / calculation actions you want to apply on the stated fields Or – any alternative actions you want to include in data manipulation/calculation

Last Week Lecture More process modelling techniques BPMN – more new notations – sub-processes, error events DFD process modelling language and its notations, levels of process modelling – context, logical & physical levels ERP Sales Processes via the Sunset case study

The Concept of Linking Tables Logical Data Model in UML Phyical Data Model in MS Access Foster Parent 0..* Cares 0..* Orphan Child Foster Parent Orphan Child 1..1 1..1 Linking Table Cares Foster-Cared Orphan Child One foster parent cares for 0..* children One child is cared by 0..* foster parent 0..* 0..* Physical Database Systems cannot handle many-to-many relationships and need the construct of “linking tables” to integrate this many-to-many relationships In other words, MS Access would implement the above physical data model, to reflect what is specified/required by the UML Data Model. In the linking table, the key is make up of 2 foreign keys: Foster Parent ID + Orphan Child ID