Lynda Spencelayh11 UNIT 16 DATABASE SYSTEMS

Lynda Spencelayh2 2 Principles of database systems zDatabases are everywhere colleges, dentists, supermarkets, banks, DVD stores, hospitals, hotels, gyms, - there are many more examples. zWithin each of these organisations the following information could be store; customers, sales, products, suppliers, purchasers, Stock, accounts, VAT.

Lynda Spencelayh3 3 zThese databases are organised in such a way that data can be easily entered, stored, edited, deleted and manipulated to support the activities of the organisation.

Lynda Spencelayh4 4 Advantages zEasy to use zrecords are easy to access and retrieve zdata can easily be manipulated in many ways zdata can be validated to ensure that it is accurate when input zeasy to store

Lynda Spencelayh5 5 Disadvantages zDatabase structures must be carefully developed to ensure that they work as efficiently as possible zthere are laws that control the use of databases zmany people feel that simply too much information is stored about us zthe cost of technology can be prohibitive

Lynda Spencelayh6 6 Terminology zAn object is something that can be designed, selected and manipulated Tables, queries, forms and reports are all examples of objects. zTables consists of rows and columns, where the row contains a record and the column becomes a record field.

Lynda Spencelayh7 7 Buttons zThe user should be able to carry out all their tasks from the form. zThey can already add a new record and change data in a record. zYou should now add a button to the form to let them delete a record. zA button is a type of shortcut that can help the user to work more efficiently. Add a button to delete records.

Lynda Spencelayh8 8 Data entry order [tab order] zThe tab will automatically guide you around the form zyou can change the data entry order study the handout and change the order

Lynda Spencelayh9 9 Query structure zUsed to interrogate the data in a database. This means filtering and sorting the data to answer questions. zThe query uses the data in the table, by searching the information in the fields and applying the chosen criteria.

Lynda Spencelayh10Lynda Spencelayh10 Queries - single criteria zEquals = this will check whether data is exactly zLess than [<] this can be used with number zGreater than [>] can also be used for dates, numbers or text. zNot equals - this can be used to find fields that do not match the data.

Lynda Spencelayh11Lynda Spencelayh11 zYou can combine two or more criteria by using AND, OR, NOT, BETWEEN these are known as multiple criteria. zStudy your mobile phone database complete activity use a multiple and single criterion. Queries - multiple criteria

Lynda Spencelayh12 Queries Wild Cards – Wild cards can be used when: zYou do only remember part of the name zWhen you want to find all records which mention a particular name. zA star represents any numbers of characters or numbers zA question mark represents one character or number

Lynda Spencelayh13Lynda Spencelayh13 Sorting records zYou can sort data via the query in design view. zYou can also sort data directly in the table. zSimply click on the relevant field and one of the sorting icons. A to[ascending order] or Z to A [descending order]

Lynda Spencelayh14Lynda Spencelayh14 Reports zA report is a printed record of data in the database. zThere are several benefits of presenting information in a report rather than just viewing the data on-screen.

Lynda Spencelayh15 Reports zIt counts the records in the report and displays the result. zit adds a heading that can be changed by the user. zIt adds the date and time. zIt adds a age number

Lynda Spencelayh16 Reports zReports are very useful if you wish to share some of the information in the database with others in a printed format. zReports can be laid out so they are easy to read and understand zReports can be used to select and present exactly the data that someone needs rather than everything in the database. zAlthough reports are intended to be printed as hard copy, they can also be transferred as electronic documents by .

Lynda Spencelayh17 Layouts zColumnar layout- each record is laid out with the fields underneath each other. The labels are placed to the left of the data. This layout ideal when there is a lot of data in each record. zTabular layout - this arranges the data in a table can be used for forms and reports if the amount of data in each record fits comfortably. zJustified layout- this displays data one record at a time. The appearance is a formal boxed style. Which fits neatly across the page, with the labels for each field above the data. It makes efficient use of space.

Lynda Spencelayh18Lynda Spencelayh18 Add buttons to link to forms and reports zImproving efficiency - the database should be easy for the user to use. Normally you will have one main form with options that link to other forms. zYou can create forms based on any queries you have created you should decided which ones will be useful to the user. z Add buttons to the main form that link to these. Remember a button is a type of shortcut to help the user to work more efficiently. zThe user may want to print out the data from one of these forms, so you can add a button that links to the report.