introduction to ms access steve shapiro computer services manager office of research services and...

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Introduction to MS Access

Steve ShapiroComputer Services Manager

Office of Research Services and AdministrationUniversity of Oregon

Region VI/VII NCURA ConferenceApril, 2011

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What is a Database?

• a comprehensive collection of related data organized for convenient access, generally in a computer

dictionary.reference.com/browse/database• This definition was found via a search of Google’s database• Databases are all around us, and all of us interact with them

on a daily basis.• Who said you can’t make your own?

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Where does MS Access fit?• http://en.wikipedia.org/wiki/Comparison_of_relational_database_management_systems

lists history for about 50 database programs

• Popular Databases:

Oracle, Microsoft SQL Server, IBM DB2, FileMaker, Ingres, MySQL, Corel Paradox, Dbase III, R:Base

• MS Access is a low-end to mid-tier database application– It runs independently on workstations for single users– It runs on servers that can be accessed by multiple users at the same time on a network– It provides a user friendlier front end to more powerful database applications such as Oracle and MS SQL Server

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What is MS Access?

• MS Access is a relational database, meaning that data is stored in multiple tables that are related to each other. – PI’s in one table, their awards in another table.

The database maintains a connection between the tables using something called a ‘key’ – a number that is the same in both tables.

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History

• Access is one of the few products originally developed by Microsoft

• Development began in the mid 1980’s• Combined with other databases that Microsoft licensed

such as R:Base and FoxPro• Released in November 1992 as a single user application for

very small (<10mb) files• Became dominant database for windows when competitors

failed to transition to Windows successfully.• Now a very stable and robust application, scaling from 1 to

many users and up to 2g of data in each file

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Today’s Session

• Will cover < 1% of MS Access capability• We won’t talk about– Security– Advanced anything• Forms, queries, front/back ends, modules, macros

– Interfacing with other databases– Advanced Data Validation– Questions on these and other topics are welcome!

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Relational Database?

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Keys relate information in different tables

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5 Major Components of AccessAccess Database Objects

• Tables• Queries• Forms• Macros• Modules

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Tables

Tables hold the information, called data

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Tables - Data Types• Text Use for text or combinations of text and numbers, such as addresses, or for numbers

that do not require calculations, such as phone numbers or postal codes (255 characters)

• Memo Use for lengthy text and numbers, such as notes. Stores up to 63,999 characters

• Number Use for data to be included in mathematical calculations, except money

• Date/Time Use for dates and times

• Currency Use for currency values and to prevent rounding off during calculations.

• AutoNumber Use for unique sequential that are automatically inserted with a new record

• Yes/No Use for data that can be only one of two possible values, such as Yes/No, True/False, On/Off.

• OLE Object Use for OLE objects (such as Microsoft Word documents, Microsoft Excel spreadsheets, pictures, sounds,

• Hyperlink Use for hyperlinks (hyperlink: Colored and underlined text or a graphic that you click to go to a file, a location in a file, a Web page on the World Wide Web, or a Web page on an intranet. Stores up to 2048 characters.

• Lookup Wizard Use to create a field that allows you to choose a value from another table or from a list of values using a combo box

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Table Encounter

• The prospect of creating multiple tables almost always intimidates beginning database users. Most often, beginners will want to create one huge table that contains all of the information they need, similar to an Excel spreadsheet.

• When thinking about which fields to add to a table, a good first guess is: What piece of information will only occur once?– Such as

• A person will probably only have one first name, though it may change– First_Name is a good candidate for the “PI” table

• A table needs at least on field that never duplicates in the same table– Two or more people can have the same first, last and middle names

• A person may have more than one award (per name)– The award title is not a good candidate for the PI table, since we don’t know how many awards a person

may have

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Queries• Queries select and modify

specific data

• “Queries convert data to information”

• They are used to populate forms and reports

• MS Access uses a visual query wizard to help novice (and advanced!) users construct queries

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Simple Queries From a Single Table• Select Award_Title from

Awards where (Award_Title Like “Exploring*”) and (Closed = False) Order By Award_Date;

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Simple Queries from Multiple Tables

• Set up relationships (Access may make you do this and if it does, will help you with a wizard)

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Simple Queries from Multiple Tables• SELECT

PIs.[First Name], Awards.Award_Title, Awards.Award_Date, Awards.Closed

• FROM PIs INNER JOIN Awards ON PIs.ID = Awards.PI_ID;

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Action Queries

• Queries can update, add or delete records from a table

• DELETE * FROM Pis WHERE (PIs.[First Name])="No Research";

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Forms

• Forms let you enter and display specific data in a customized format.

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Basic Types of Forms• Single Record

• Datasheet

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Form Controls

• Bound Controls– Are directly ‘attached’ to the data and will update

as you leave the field on the form• UnBound Controls– Have to be manipulated with program code

• Calculated Controls– Do not exist in the data tables. They are derived

based on other controls or fields in the database

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Types of Controls• Text Box: Displays and allows user to enter data• Label: Displays static text• Button: Does something by runnning macros or VBA Code• Combo Box: A drop down list of values• List Box: A list of values• SubForm: a form of related data within a form• Shapes: boxes, lines, images• Check Boxes: Yes/No or True/False• Option Groups: choose one option from a group• Toggle Buttons: enabled or not enabled• Tabs: for forms with lots of data, multiple tabbed pages• Charts: Display data in graphical format• More…

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PropertiesWhat can a Control look like and how can it act?

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Events – Making Access Do Something

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Visual Basic Code in a Form

• Behind a button

Private Sub btn_Close_Click() DoCmd.Close acForm, frm_PI_Awards End Sub

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Data Validation and formattingIn the Table

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Data ValidationOn the Form

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Macros

• Wizard driven tool to automate repetitive tasks

• Can be very simple or very complex

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Reports

• Reports display and print formatted data– Text• Form Letters, columnar reports, grouped reports

– Graphics– Sub Reports– Export to other formats, such as spreadsheet,

word processing– Wizard driven or drive yourself

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Designing a Report

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Modules

• Modules contain Visual Basic for Applications program code as subroutines or functions

• Visible from anywhere in the Application:– tables, queries, forms, macros and reports

• Subroutines typically do something• Functions do something and return a result

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VBA Code

• Wizard and context assistants help write code• Almost, but not quite understandable

Public Function Activate_Detail_Form(My_Form As Form) Dim db As Database Dim rec As Recordset Set db = CurrentDb() Set rec = db.OpenRecordset("tbl_sys_Color_Scheme", dbOpenSnapshot) rec.MoveFirst My_Form.FormHeader.BackColor = rec!Detail_Header_BackGround_Color My_Form.Label1.ForeColor = rec!Detail_Header_Font_Color rec.Close Set rec = Nothing Set db = Nothing My_Form.Repaint End Function

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Getting Started with Access

• Database development is quite unlike most other programs used to create information in a computer, such as word processing or spreadsheet.

• Database development requires prior knowledge

• A beginning user opening Access for the first time likely has no idea where to start. Unlike Word or Excel, you can’t just ‘start typing’

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Create Ribbon

• Starting point for all new objects in the database

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Conventions

• Application developers like to label objects in their applications in such a manner that when they go back to look at it several years later, they can figure out what they’ve done.

• We use prefixes and suffixes when we name things:– Tables: tbl_Awards– Forms: frm_Awards– Buttons on forms: btn_Form_Close– Reports: rpt_Reports– Text fields within a table: PI_Name_txt– Integer Fields within a table: Award_Number_txt

• Spaces in object names are allowed, but dangerous. Use underscores “_” or enclose object names in brackets [tbl Awards]

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Educational Materials

• Office.microsoft.com– Templates Databases

• My favorite Book:– Microsoft Access 2010 Bible• By Michael Groh

• Search Engine: [Access 2010 and your question]

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