A Painless Introduction to MS Access Databasing

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A Painless Introduction
to MS Access Databasing
Yannick Pouliot, PhD
Bioresearch Informationist
lanebioresearch@stanford.edu
Lane Medical Library & Knowledge Management Center
4/20/07
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Preliminaries


Launch MS Access
Open Simple1.mdb


File/Open
Using the Help  don’t neglect it!

Exercise: ask the Office Assistant for “select
syntax”
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Contents






Familiarization with MS Acces
Understanding a simple database
Basics of SQL querying
Creating a simple database
Loading database via MS Excel
Tools for running SQL queries



Installation (Windows)
Selected databases
Resources & cheat sheet
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Resources – MS Access
Available as eBook
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Available as eBook
4
Resources – Excel/MS Query
In Lane catalog
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Resources – MS Access
Free Online Training Resources




Using an Access database to store and information (2 min)
http://office.microsoft.com/en-us/assistance/HA011709681033.aspx
Creating a database from Excel (5 min): http://office.microsoft.com/enus/assistance/HA012013211033.aspx
Creating tables in Access (50 min):
http://office.microsoft.com/training/training.aspx?AssetID=RC061183261033
Writing queries (50 min):
http://office.microsoft.com/training/training.aspx?AssetID=RC010776611033
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Why Bother
with MS
Access?
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Why MS Access?

More: http://office.microsoft.com/enus/access/HA010429181033.aspx
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Definitions,
Definitions…
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Definitions


Database: Collection of tables 
Table
 Collection of records that share a common fundamental
characteristic


Schema


E.g., patients and locations can each be stored in their own table
A view that inter-relates tables to each other
Record
 Basic unit of information in a relational table

E.g., 1 record per person
A record is composed of fields
Query
 Set of instructions to a database “engine” to retrieve, sort and
format returning data.




E.g., “find me all patients in my database”
Database engine
 Software application that stores the data and enables querying
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Table and Field Definitions
How It Looks In Access…
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Main Relational Database Engines
 Oracle

MS Access


MS SQL Server
Filemaker

MS SQL Server
 MySQL


Postgress
Sybase
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Understanding
Relational
Databases
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Understanding the Relational Principle: A
Simple Database
“join”





Every patient gets ONE record in the Patients table
Every visit gets ONE record in the Visits table
Rows in different tables can be related one to another
using a shared key (identifier  number unique to table)
There can be multiple visits records for a given patient
There can be multiple tissue records for a given patient
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The Relational Principle in Action

Related records can be found using a shared
key

Shared key = identifier that is:



unique to each table
Can be referenced by another table
Example: Patients.ID = Visits.PatientID
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The Database Schema: Your
Roadmap For Querying

The schema describes all tables and all fields




Describes relationships between tables
Crucial in enabling retrievall of desired data
Simple example:
Very important


Must understand schema for accurate querying
Wrong understanding = wrong results
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Example: The Schema for SRI’s
BioWarehouse System
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Querying MS Access
or any relational database…
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How Relational Databases Are
Queried

Querying = extracting information out of the
database


… and into something, e.g., Excel
This is done using the Structured Query
Language (SQL)
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Introducing The SQL Select Statement


Good news: This is the
only SQL statement
you need to understand
for querying
Exercise: run
SuperSimpleQuery1 in
Simple1 database
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SELECT LastName, FirstName
FROM Patients
20
Basic Syntax of Select Statement
SELECT field_name
FROM table
[WHERE condition]
[ ] = elective
Example:
Select LastName,FirstName
From Patients
Where Alive = ‘Y’;
Important: Everything is MS Access is case sensitive
 LastName ≠ lastName
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Realistic
Querying With
the MS Access
Query Builder
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A More Complete Description of Select
Statement
SELECT [DISTINCT|COUNT] field_list
FROM table_list
[WHERE conditions]
[GROUP BY field_list]
[ORDER BY field_list [ASC | DESC] ]
more: http://office.microsoft.com/enus/access/HP010322651033.aspx?pid=CH010410171033
Includes examples and descriptions of each
SELECT operator (e.g., “group by”)
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Meaningful Queries in Acces
Exercises - Database: Simple2.mdb
1.
2.
Returning ordered records
Counting records

LifetimeNumberFAQs1


LifetimeNumberFAQs2

3.
4.
5.
Exercise: how many FAQs per day?
Demo: creating Pivot Tables
Generating averages

Querying from a query!
Change order of columns
Change sorting of rows
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Uploading
Data in MS
Access
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Importing Data Into Acces From
Access
Important
 Column headers in Excel file must match those of
columns in Access target table


Must ensure that data in Excel columns is of correct
type (text, number, date)


Blanks (not empty cells!) are nasty
Exercise: Loading data via Excel


No spaces, weird characters
File: LoadingData.xls
Demo: http://office.microsoft.com/enus/access/HP010950951033.aspx
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Creating an Access DB from Excel


One table per Excel worksheet
Demo: http://office.microsoft.com/enus/access/HA012013211033.aspx
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Cool Things You Can Do In Access

Store entire files in records

Excel, Word, sounds, pictures anything
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Extras
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Creating Forms Using MS InfoPath


Really the easiest way to
create interfaces to
Access
10 min of work


Probably 30 for you 
More:
http://office.microsoft.com
/enus/access/HA0111995010
33.aspx
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Querying With MS Excel

MSQuery, an unknown hero



Free
Facilitates writing of a SQL query  graphical
First, need to find it!

Search for “MSQRY32.EXE” using “Search for Files or
Folders”



On my disk, it is located in C:\Program Files\Microsoft
Office\OFFICE11
Once you find it, create a shortcut to it and rename it e.g.
MSQuery


Search hidden files and folders
move the shortcut to a desired location
Also needed: creating a data source name
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To Conclude…


If using Excel is a headache, use MS Access
Access can work very well on its own



reasonably easy to learn/use..
Lots of free resources to quickly learn how to use
it
MS Access + Excel = dynamite
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Yannick Pouliot, PhD
lanebioresearch@stanford.edu
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The NittyGritty Details
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How to Query Using MS Query
Steps
1. Make sure you have the requisite driver (next
slide)
2.
3.
4.
Create a Data Source Name (Windows only)
Write your query
Get the results back into Excel!
See Lane videorecorded class Managing
Experiment Data Using Excel and Friends:
Digging Out from Under the Avalanche for lots
more details.
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Step1: Getting Drivers
Essential for SQL Querying

A driver is a piece of software that lets your
operating system talk to a database

Installed drivers visible in ODBC manager


Each database engine (Oracle, MySQL, etc)
requires its own driver



“data connectivity” tool
Generally must be installed by user
Drivers are needed by Data Source Name
tool and querying programs
Require (simple) installation
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MySQL Driver: Needed to Query
MySQL Databases


Windows: Download MySQL
Connector/ODBC 3.51 here
Must be installed for direct querying using
e.g. Excel

Not necessary if you are using the MySQL Query
Browser
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Oracle Driver: Needed to Query
Oracle Databases

Installing “client” software will also install
driver




Windows: Download 10g Client here
Mac: Download 10g Client here
Free Oracle user account required to
download
Must be installed if you are querying
using MS Query or any other query
browser involving Oracle
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Step 2: Creating a Data Source Name


A Data Source Name (DSN) tells programs
on your PC where and how to query a
database
Populating the fields:




Data Source Name: Unique name of your choice
Description: anything
Server: exactly as given by the database provider
Port number: as specified by database provider

Defaults: MySQL: 3306; Oracle: 1521; MS Access: N/A
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Words of Caution

Easy to build queries that


Retrieve nonsense
Never complete, end up completely bogging down
the database


Scotty to Captain Kirk: “Where going in circles, and at
warp 6 we’re going mighty fast…”
Understanding schema is only way to prevent
that

Not always easy…
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Resources – SQL
The Language to Query Relational Databases



Beginning SQL, Wilton P & Colby JW: E
http://jenson.stanford.edu/uhtbin/cgisirsi/5AG
uKeptoD/GREEN/59960102/9#holdings
Oracle SQL*Plus, Gennick, J.
Beginning MySQL: e-book
http://site.ebrary.com/lib/stanford/Doc?id=101
14227
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The Relational Principle in Action

Related records can be found using a shared
key

Example: Patients.ID = Visits.PatientID
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MySQL Query Browser
MS Query
MySQL only
All (e.g., Oracle)
No
Yes
Dr
iv
er
?
an
ag
er
?
BC
M
Us
e
of
High
OK
O
D
Tool
Ea
se
Da
ta
ba
se
s
SQL Querying…With What?
Yes
No
Other query browsers exist but are more sophisticated



= more complex
Example: PL/SQL Developer, from Allround Automations
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