Download Slide 1

So What’s Access?
It’s a Database
So What’s a Database?
Original Slides Courtesy of Prentice-Hall, 2008
Edited by Jack Fassel, 2008
1
Topics
•
•
•
•
•
•
Databases and their uses
Database components
Types of databases
Database management systems
Relational databases
Information systems
2
Access (a Database)
• Access let’s you:
– Store data
– Sort data
– Organize data
– Query (question, what-if) data
• Why not just use a list or lists? – it all
sounds like Excel
– Complex information
– More than one person access
3
Databases Solve
• Data Redundancy
(storing the same data more than once)
• Data Inconsistency
(is the column a zip code? Then make sure it’s
a zip code not some guy’s name)
• Incomplete Data
(970 is not a valid zip – 97030 is)
4
Databases
• Electronic collections of related data
• Help us organize data
• Turn data into information
5
Advantages of Using Databases
• Store and retrieve
large quantities of
information
• Enable information
sharing
• Provide data
centralization
• Promote data
integrity
• Allow for flexible use
of data
Financial Aid
Recording grades
Student Registration
Student
Information
Student housing Database
Parents
6
Database Terminology
• Field
Field Name
– Category of
information
displayed in
columns
– Each field has a
field name
7
Database Terminology
• Data types
–
–
–
–
–
–
–
Text
Numeric
Computational
Date
Memo
Object
Hyperlink
8
Database Terminology
• Record
– A group of related
fields
Record
9
Database Terminology
• Table
– A group of related records
Table
10
Database Terminology
• Primary key
– A field value unique to a record
Primary Key
11
Database Types
• Relational databases
– Organize data in a table
– Link tables to each other through their primary
keys
• Object-oriented databases (they exist; but
we don’t care for now)
• Multidimensional databases (they exist;
but we don’t care for now)
12
Database Management Systems
(DBMS) including Access
•
•
Application software designed to capture
and analyze data
Four main operations of a DBMS are:
1.
2.
3.
4.
Creating databases and entering data
Viewing and sorting data
Extracting data
Outputting data
13
1. Creating Databases and
Entering Data
• Create field
names:
– Identify each
type of data
– Data dictionary
– View scene from
within “design
view”
14
Creating Databases and
Entering Data (cont)
• Create individual
records:
– Key-in
– Import
15
Data Validation: So like data gets into each
column (i.e. SSN can’t have a name entry)
• Validation
– Process of ensuring data
entered into the database
is correct (or at least
reasonable) and complete
• Validation rules
–
–
–
–
Range check
Completeness check
Consistency check
Alphabetic/numeric checks
16
2. Viewing and Sorting Data
Before sort
• Browse through records
• Sort records by field
name
• ALL data in tables still
there
After sort
17
3. Extracting or Querying Data
•
Query “Slicing/Dicing”
– A question or inquiry
– Provides records based on
criteria
– Structured query language
(SQL) occurs “behind” the
scene
-- Table contents “is” SLICED to
a subset of the original
contents (if query “saved”)
SQL
18
4. Outputting Data
• Reports:
– Printed (i.e. mailing labels)
– Summary data reports
• Export data
19
Relational Database Operations
• Relational databases
organize data into tables
based on logical groupings
• Relationships are links
between tables with related
data – MANDATORY!
• Common fields between
tables need to exist
• Normalization of data
(recording data once)
reduces data redundancy
20
So let’s get started
• Start Access 2007 and you should get
something that looks like the screen on the
next slide
21
The opening screen
22
The opening screen on the
previous slide -Contains a number of templates (we’re not
using) but the Office button in the upper
left hand corner is still the same
Click on it to “open” an existing database
23
A database has just been opened; notice the Security
Warning which requires you to click the “options” button to
“enable”; also notice that this database has two tables
24
Double click a table name to open table (“Departments” was opened
below which contains 5 columns (or fields) and 12 rows (or records))
From this view you can add, delete rows, move from row to row or
column to column, even add/delete
25
SORT: Like Excel, you can SORT ALL the rows. The table
below is sorted by the last_name column by: Click column
title, then, Home_tab, Sort_Filter_Group, A_Z button
26
FILTERS “Hide” portions of the table (the information is still there – just
“hidden”) To FILTER: Click the column title you want to filter (example below is
on dept code), home_tab, sort_filter_group, click the filter “funnel”, dialog box
appears)
27
Example below checks ONLY the CIT value of the
column
28
Example below shows the filtered CIT data resulting in 4 rows
displayed. Notice that the “Toggle Filter” button is in orange in the
Sort_Filter group. Filters are ONLY for temporary “viewing”; don’t save!
29
QUERIES are “questions” about the table. Assume you had
3 million records of members and their addresses, but you
only wanted to know those that lived in zip code 97030 so
that you could printout out mailing labels. You could print all
3 million labels and hand-sort/pull just those in zip code
97030 – which would be a complete waste of
time/resources OR, you could “slice” the original table to
“create” a table containing ONLY those in zip code 97030.
To “slice” the table, use a Query. The Query can specify
any number of criteria to get the resulting sub-table needed
AND saving the Query by name allows you to use the same
query over and over again even though the contents of the
table changes with time.
30
To CREATE a QUERY using the DESIGN VIEW, Select
the “Create” tab from the ribbon, and click “Query Design”
from within the “Other” group (as seen below)
31
You can select one or all tables. The example below
selected the departments table by highlighting and clicking
the “add” button
32
Below shows the Design view query screen after the “add” button is clicked
followed by the “close”. Notice that you see the “Departments” shown with all
it’s column headings and that the “dept code” column has a “key” next to it –
the primary key, which states that all column entries must be unique.
33
We want to know/show, from the original
“Departments” table the following:
- Dept Name
- Dept Chair
- Division
- of ONLY those Divisions that are “Arts &
Sciences”
Instead of 5 columns, the query will result in 3
columns.
Instead of 12 rows, the query will result in ONLY those
rows containing “Arts & Sciences” (counting them
from the original “Departments” table, there should be
3 rows)
34
To get started, notice the down arrow in the lower
portion of the screen, in the first column/first row,
the “field” row
35
By clicking that arrow, a menu appears containing
all the “departments” table column names
36
Since the first column desired is “dept name”, a click from the menu results in
selecting that column. Notice also in the Table listing, the table shown is
“departments” If there was more table in the query, each tables name would be
listed by column
37
The next column to be shown is Dept Chair, selected the
same way but in the 2nd column
38
The third and last column in the query is the Division
column – notice the check marks – all three columns will be
displayed when the query is run.
39
To specify ONLY the “Arts & Science” be shown,
the “criteria” for that column is entered as shown
below. The column name must be in single quotes
40
So how do you run the query? Look at the upper
left corner below the ribbon. There’s a RED
Exclamation point
41
The query has run. The results are display (as
expected)
42
To save the query, click the “X” on the query and
the dialog box appears. Select “Yes”
43
Give the query a name (otherwise Access will call
it Query 1), then click “ok”
44
Called the query “Arts & Sciences”
45
The query is saved and can be retrieved, like any
other object, from the list at the left. Any object
can be selected and viewed
46
Under the “queries” objects, two queries are
shown. The Arts & Sciences is the query just
created. Double click the name to ‘view’ it
47
Query viewed
48
To close Access, select the Office Button in the
upper/left most area
49