Database Management System Conducted By Provincial Computer Resource Centre Gurudeniya Jayaratna Alahakoon

6/13/2005PCRC Central Province2 What is a Database Database is a collection of Information related to a particular subject. Ex. School Database Employee Database Telephone Directory

6/13/2005PCRC Central Province3 What is a Table Table is a collection of records specific to the topic Teacher table Student table Class table

6/13/2005PCRC Central Province4 What is a record Record contained information about a single item in your table( Collection of fields) EX. NameAgeSe No. A M G Nishantha 27No.1222 B I Perera 28NO.1133

6/13/2005PCRC Central Province5 What is a field Field is a piece of data within a record. Ex Name Address Age

6/13/2005PCRC Central Province6 What is primary key The field or combination of fields which can be used to identify a record from a table uniquely is called as a primary key

6/13/2005PCRC Central Province7 What are the Database Software Dbase 3+ FoxPro Oracle Access

6/13/2005PCRC Central Province8 What is MS Access Database Management Software introduced by Microsoft company

6/13/2005PCRC Central Province9 What are the different type of Objects available in MS Access Tables Queries Forms Reports Pages Macros Modules

6/13/2005PCRC Central Province10 What is a Tables It is the most important object in the database. Tables are used to enter data. Single database may contain one or more tables. Table contain rows and columns. Row represent Record and column represent Field. class ClassNoLocationTeachersize 10DT DT ACT BCT CCT BT BT BT BT ADT CT ADT CT CT CT004540

6/13/2005PCRC Central Province11 Queries Quarry can be used to select specific records, or filter records, fields using a criteria

6/13/2005PCRC Central Province12 Forms Forms can be used to enter data or view data of a table or a query in more user friendly manner

6/13/2005PCRC Central Province13 Reports Reports are used to produce printed output of Data of table (Tables) or Query (Queries)

6/13/2005PCRC Central Province14 Macros Macros can be used to automate functions

6/13/2005PCRC Central Province15 Modules Allows us to write functions that can be used in queries.

6/13/2005PCRC Central Province16 Type of data in MS Access 1.Text 2.Number 3.Date/Time 4.Currency 5.Memo 6.OLE 7.AutoNumber 8.Hyperlink 9.YES/NO (Logical) 10.Lookup Wizard

6/13/2005PCRC Central Province17 SettingType of dataSize Text (Default) Text or combinations of text and numbers, as well as numbers that don't require calculations, such as phone numbers. Up to 255 characters or the length set by the FieldSize property, whichever is less. Microsoft Access does not reserve space for unused portions of a text field.FieldSize Memo Lengthy text or combinations of text and numbers. Up to 65,535 characters. (If the Memo field is manipulated through DAO and only text and numbers [not binary data] will be stored in it, then the size of the Memo field is limited by the size of the database.) Number Numeric data used in mathematical calculations. For more information on how to set the specific Number type, see the FieldSize property topic. 1, 2, 4, or 8 bytes (16 bytes if the FieldSize property is set to Replication ID).

6/13/2005PCRC Central Province18 SettingType of dataSize Date/Time Date and time values for the years 100 through bytes. Currency Currency values and numeric data used in mathematical calculations involving data with one to four decimal places. Accurate to 15 digits on the left side of the decimal separator and to 4 digits on the right side. 8 bytes. AutoNumber A unique sequential (incremented by 1) number or random number assigned by Microsoft Access whenever a new record is added to a table. AutoNumber fields can't be updated. For more information, see the NewValues property topic.NewValues 4 bytes (16 bytes if the FieldSize property is set to Replication ID). Yes/No Yes and No values and fields that contain only one of two values (Yes/No, True/False, or On/Off). 1 bit.

6/13/2005PCRC Central Province19 SettingType of dataSize OLE Object An object (such as a Microsoft Excel spreadsheet, a Microsoft Word document, graphics, sounds, or other binary data) linked to or embedded in a Microsoft Access table.linkedembedded Up to 1 gigabyte (limited by available disk space) Hyperlink Text or combinations of text and numbers stored as text and used as a hyperlink address. A hyperlink address can have up to three parts:hyperlink address text to display— the text that appears in a field or control. address— the path to a file (UNC path) or page (URL).UNC pathURL subaddress— a location within the file or page. screentip— the text displayed as a tooltip. The easiest way to insert a hyperlink address in a field or control is to click Hyperlink on the Insert menu. Each part of the three parts of a Hyperlink data type can contain up to 2048 characters.Hyperlink Lookup Wizard Creates a field that allows you to choose a value from another table or from a list of values by using a list box or combo box. Clicking this option starts the Lookup Wizard, which creates a Lookup field. After you complete the wizard, Microsoft Access sets the data type based on the values selected in the wizard.list boxcombo boxLookup field The same size as the primary key field used to perform the lookup, typically 4 bytes. primary key

6/13/2005PCRC Central Province20 Normalization First Normal Form (1NF) Second Normal Form (2NF) Third Normal Form (3NF)

6/13/2005PCRC Central Province21 First Normal Form (1NF) If every attribute of R (Table) is atomic then R is in 1NF ( None of the attribute is composite or multi valued) EX. Employee (Emp_No, Name, Add, Salary) Name may have two or more parts but it is considered as one string

6/13/2005PCRC Central Province22 Second Normal Form (2NF) A relation R is in 2NF if every non_prime attributes of R is fully functionally dependant on the primary key of R EX. Emp_Proj( NIC, PNO, Hours, Ename, Pname, Plocation) NIC,PNO Hours (Full dependent) NIC,PNO Ename (partial dependent) Not in 2NF Employee( NIC, Ename) Project ( PNO, Pname, Plocation) Hours cannot be placed in any of the above hence create another relation Emp_Proj (NIC, PNO, Hours)

6/13/2005PCRC Central Province23 Third Normal Form (3NF) 3NF is based on transitive dependancy A relation is in 3NF, if it satisfy 2NF and no none prime attribute of R is transitive dependant on the primary key Salesman(E_No, E_Name, Sale_amount, Salary, Discount) E_No Sale_amount E_No Discount Sale_amount Discount This is transitive dependant hence not in 3NF