AIN102 Microsoft Access Queries

Accelerated Computer Training for Working Professionals Admissions Case
Orange Coast Database Associates Course (800)355-9855 or http://ocdatabases.itgo.com
Orange Coast
Database Associates
Specializing in Microsoft Office,
Access, SQL, and related technologies
Classes custom designed forWorking Professionals
http://www.dhdursoassociates.com
San Juan Capistrano, CA
(800)355-9855
AIN102 Microsoft Access Queries

Admissions AIN1021
AIN102 – Access Query Design
Introduction to Access Queries for
experienced Windows users
P.O. Box 6142
Laguna Niguel, CA 92607
949-489-1472
http://www.d2associates.com
AdmissionsAIN1022
AIN102 Contact Information
P.O. Box 6142
949-489-1472
slides.1@dhdursoassociates.com
Copyright 2001-20011 All rights reserved.

AIN102 Notes
 This course is based on an earlier course,
SQL200A, which was focused on using SQL in
the Access environment. As such the
screenshots still reflect SQL view as well the
Query Designer view. This is actually a plus.
AdmissionsAIN1023
AdmissionsAIN1024
 Introduction (s)
 Facilities
 Course Packet (May vary by course or class)
– Student questionnaire in front
– Collaterals (Map, Catalog, Etc.)
– PowerPoint handouts for all sessions
– Evaluation form in back
– Training Certificate

AdmissionsAIN1025
Orange Coast Database Associates
 Loose association of local University instructors and IT
Professionals.
 Started in 2004
 Training
– Open Enrollment (public classes in San Juan Capistrano using
standardized material)
– On-site (custom classes for groups)
– Private desk side training for individuals
 Consulting & Programming (incl. offshore)
AdmissionsAIN1026

AdmissionsAIN1027
 Quick pace for experienced windows users
 Assumes some prior knowledge of Access
 End-user, not programmer, oriented
 Somewhat structured towards personal use for
analysis and reporting
AdmissionsAIN1028
 Select Queries
– Filter Criteria
– Calculations
– Joins
– Grouping
 Action Queries
– Maketable
– Append
– Update
– Delete
 Union
Course Topics:

AdmissionsAIN1029
Approach:
SQL View Used in code; but helpful in
understanding what a query
does
Query Designer Use to construct queries
Access has many ways to accomplish tasks. Queries can be
constructed using SQL View or the Query Designer. This
course focuses on the latter.
AdmissionsAIN10210
 2 Sessions
 Lecture
 Demo
 Extensive student “hands-on”
 Exercises are cumulative – later
examples build on objects created
earlier
Course Format:

AIN102 Resources
 Manuals can be downloaded from SlideShare.
 Slides can be viewed on SlideShare…
http://www.slideshare.net/OCDatabases
AdmissionsAIN10211
AdmissionsAIN10212
 Session 1
– access-qdes-s1-ad.ppt
 Session 2
– access-qdes-s2-ad.ppt
Course Schedule (3 hour sessions):

1
AIN102
Access Query Design
Orange Coast Database Associates, Inc.
949-489-1472
AIN102
Access Query Design
Module 1 – Relational Database Background,
Basic Single Table Retrieval Operations

2
AIN102 Module 13 Admissions AIN102 Module 13
AIN102
 Session 1 – Review of Relational Databases
and Single Table Retrieval, Functions and
Operators
 Session 2 – Multi-table retrieval, Subqueries,
Unions, Action Queries, Indexes
AIN102
 Lecture/discussion with demonstrations
– Mostly practical, but a dose of “theory”
 Assumes some familiarity with MS Access
 Hands-on
 Exercises (Mostly cumulative)
 About 3-4 hours per module
 Frequent breaks

3
Module 1
 Concepts
– Relational
databases
– SQL
– Access Query
Designer
 SELECT Query
– Basic
– Filter criteria
– Complex criteria
• Field Operations
• Functions
• Operators
• Calculated fields
• Concatenation
Microsoft Access Query Design
 Course focus is Microsoft Access Query Design
 Queries are widely used for:
– Database administration
– Enterprise application development
– Data driven web sites
– Retrieving and modifying data in MS Access databases
 A foundation skill for eBusiness and almost all major
business applications that use relational databases

4
Access Query Design and SQL
 Class database will be MS Access – the SQL
engine Access uses is called JET
 A basic knowledge of Access is assumed
 Focus of this class will be on the query
designer, with SQL used from time-to-time to
explain concepts
Relational Database Basics
 Storage
 Databases
 Tables
 Rows
 Columns
 Indexes
 Views
 SQL interface

5
Storage
 In Access one file with extension mdb. I.e
mydatabase.mdb.
 Database splitter can be used to split it into
two parts – a front end and a back end.
 Interface to physical storage via the “JET”
database engine. This is the behind-the
scenes-workhorse.
Databases
 In the Access world refers to all objects
stored in the mdb.
– Tables
– Queries
– From
– Reports
– Macros
– Code modules

6
Relational Database Table
Sample Access Database

7
Database Relationships
Approaching Query Design
 Try to build queries a step at a time
 Save existing queries that are working
as you like; modify them with a new
name when building a modified query
 Try looking at the generated SQL code
from time-to-time

8
Query Types
 Select
 Action
– Update
– Delete
– Insert
– Maketable
 Special use queries
– Data Definition Language (DDL)
– Union
– SQL pass-through
DDL
 Data definition language (DDL) to create and
modify tables, etc.
– Create, alter, drop, etc.
– Must be “hand-coded” in Access
– But can be useful for database administration
 Done in MS Access via SQL Specific Queries
– Will not be covered in the course

9
MS Access DDL Queries
DCL
 Data Control Language (DCL) to control user
rights, etc.
– Grant
– Revoke
– Constraints
 Used primarily in enterprise databases
 Can be done in Access but not covered in
this course

10
DML
 Data Manipulation Language (DML)
– Select Query
– Append Query
– Update Query
– Delete Query
– Maketable Query (a special type of Select)
– Union Query (really combined Selects)
 MS Access Query Designer will create these
statements “behind the scenes”
MS Access Action Queries

11
Other Access Queries
 Crosstab
 Pass Through – used to pass an SQL
statement directly to a back end database
w/out processing by Access
Sample Database
 Before we continue…
 Load the sample database if you haven’t
already

12
AIN102 Module 123
Query Designer
Admissions AIN102 Module 123
Right click anywhere
for SQL View
Double click or drag
to add a field
Double click to add a
table
SELECT Queries
Basic Syntax:
Select column-list or *
From table-list
* Means all columns

13
MS Access SELECT Query
Drag and Drop
or double click
MS Access SELECT SQL

14
Simple Select Query Results
SELECT w/ Where
Filters retrieved rows
Syntax:
SELECT column-list
FROM table-list
WHERE selection-criteria

15
Comparison Operators
 < less than
 > greater than
 <= less than or equal
 >= greater than or equal
 = equal
 <> not equal
SELECT w/ WHERE

16
SELECT w/ WHERE
SELECT w/ WHERE Results

17
Complex Filters
Follows normal boolean logic
Select PatID, LastName, etc…
From patients
Where (LastName = “Thomas” or
birthdate < #1/1/95#) and city =
“Corona”)
Complex Filter
AND

18
Select w/ Complex Where
Complex Filter Results

19
Special Operators
 LIKE
 IN
 BETWEEN
 IS NULL
Like (“Wild Card Matches”)
 Where customer_last_name like “Jo*”
– *= string of characters
 Where customer_last_name like “Jo?”
– ? = exactly one character
Access actually allows more sophisticated Unix style
search patterns as well – see help.

20
LIKE
Names ending in “S”
LIKE
Names ending in “S”

21
LIKE Results
IS NULL
Select columnns
From clients
Where zip IS NULL
SQL (including JET) uses three valued logic.
Must use IS NULL to test for unknowns. A null is
NOT the same as blank or empty.

22
IS NULL
IS NULL

23
IS NULL Results
OK. Now try finding all patients with a blank address. Was
the above row retrieved? Why or why not?
IN
Select *
From patients
Where lastname IN (“Smith”,
“Thomas”, “Juarez”)
Note: what is inside parentheses is a list. Later we
will replace the list with a subquery which
generates the list items.

24
IN
IN
List of values

25
SELECT w/in IN Results
BETWEEN
SELECT *
FROM admissions
WHERE admit_date BETWEEN
#10/1/2001# and #12/31/2001#
Note: between is inclusive

26
BETWEEN
BETWEEN Results

27
Removing Duplicates
SELECT DISTINCT PatNo
FROM admissions
List once each employee who has a
labor ticket
Removes duplicate rows from result set
DISTINCT

28
Distinct Results
W/out Distinct With Distinct
Sorting – ORDER BY
DESC will sort in descending order
Basic syntax:
SELECT column list
FROM table list
WHERE selection criteria
ORDER BY column list [DESC]

29
Select *
From patients
Where state in(“CA”, “OR”, “WA”)
Order by birthdate desc
Example:
List patients in Pacific Coast sorted
by youngest to oldest
Note: modify the “select_in” query

30
Sorting – Results

31
Query/SQL Exercises
 List all patient numbers, etc. for patients who co-
paid more than $20; sort by co-pay amount,
largest first
 List diagnostics that contain b, d, or q in the
diagnostic code
 List the patient id’s for admissions in the fall (Sep,
Oct, Nov) of 2001 and 2002
Calculated Fields
Example:
Select a + b as result
Syntax:
SELECT expression AS new
column name
Result is a “column
alias”

32
Calculated Fields
New column name
Follow name with “:”
Calculated Fields

33
Calculated Fields - Results
Concatenation
 “Adds” two character fields using “&” symbol
 Useful for formatting names, addresses, etc.
 Example:
– Select firstname & “ “ & lastname as fullname

34
Concatenation
Sort, but don’t
show
Concatenation

35
Concatenation
Single column with full
name, sorted by last name
Tip: handy for reports
SQL Exercises
 List all the patients with a “fullname” field;
sorted by last name. Add a calculated field
which shows their loaded copay (copay *1.5).
Show the fullname, but not the individual
names.

36
End Session 1
Next session: multi-table
operations, subqueries, unions,
action queries, indexes

1
AIN102
Access Query Design
Module 2
P.O. Box 6142
949-489-1472
Module 2
 Part 1
– Miscellaneous Functions
 Strings
 Dates
– Summaries (Grouping)
 Part 2 – Joins,
subqueries
– Inner join
– Outer joins
– Subqueries
 Multi-valued
 Single-valued
• Part 3 – Unions,
Action Queries,
Indexes
• Unions
• Maketable Query
• Delete
• Append
• Update
• Indexes

2
String Manipulation
 Trim
 Substring
 UCase, LCase
 Left, Right
 See help for others
String Manipulation

3
String Manipulation
String Example

4
Date Functions
 Numerous date functions
– DatePart
– DateDiff
– DateAdd
– Etc.
 Often used:
– Year
– Month
 Ex: where year(birthdate) = 1999
DateDiff
 How long did patients stay in weeks?

5
DateDiff results
Note: Access has many date functions with many options.
Ex: Date Function – Month()

6
Ex: Date Function – Month()
Result of Month Function

7
Summary Functions
 Count
 Sum
 Min
 Max
 Avg
 Often used in conjunction
with grouping
Summary Functions in Access
Click the sum symbol
Adds a total row

8
Summary Functions - Syntax
Basic syntax:
SELECT function(column)
FROM table
WHERE filter-condition
GROUP BY column-list
HAVING group-filter
Group by all columns to left of one(s)
you to want aggregate
Simple Column Summaries
This query counts patient admissions In the year 2001

9
Simple Column Summaries
Simple Record Count

10
“The COUNTS”
 Count(*) – counts records
 Count(fieldname) – counts non–null
occurrences of field name
 Count (distinct fieldname) – counts distinct
occurrences, but not supported in access
Grouping
 Organizes results into summary rows, one per
group
 Groups can have sub groups which have sub
groups and so on….

11
GROUP BY in Query Designer
GROUP BY Problem
Not an aggregate
or group
You will see this error a lot. Not to worry. It happens to everyone!

12
Group By Results
Having
 Restricts the groups returned
 Operates on the groups after they have been
formed
HAVING
(((Admissions.Diag_Code)
Like "a*"))

13
Having – SQL View
 Restricts the groups returned
 Operates on the groups after they have been formed
HAVING

14
HAVING Results
AIN102
Access Query Design
Part 2 – Joins, Subqueries

15
Database Design
Diagram of the database for reference in joins
Joins
 Used to combine columns from more
than one table
 Several types
– Inner
– Outer
 Left
 Right
– Others (not covered)
 Full Outer (Not supported in Access)
 Cross
 Self
 Non equal

16
Inner Join
 Pairs each row from first table with
corresponding row from second table over
the “join column” or “linking column”
 The result only contains rows where there is
a match over the join column in both tables
 The default join in most databases
Inner Join Syntax
Basic SQL 92 Syntax:
SELECT column-list
FROM table1 [AS alias]
INNER JOIN table2 [AS alias]
ON join-condition

17
Table Aliases
 Shorthand name for a table
 Used in more complex queries
Select t.id, s.lname
From _traveler as t
Inner join xLU_Staff as s
On t.staffid = s.staffid
Table alias
Inner Join Basic SQL Example
Basic Example: Add patient names to
admissions data
Two join tables
Join condition

18
Inner Join Query Design
Inner Join Results

19
Inner Join over Multiple columns
 Note that that the join condition can apply to
multiple columns if desired
 Used with composite keys
Select ….
From tablea as ta
Inner join tableb as tb
On ta.key1 = tb.key1
And ta.key2 = tb.key2
Joining More than Two Tables
 Can join several tables in one select
 Try to limit to three or four
 Demonstration example

20
3 Table Query Results
More on Aliases
 Can be set in Query
Designer, too, by
right clicking on a
table
 Useful for debugging
top level queries as
we shall see later

21
Outer Joins
 Left
– selects all rows from the left or first table, even if no match
exists in the other table
– Widely used in commercial practice, esp. for reporting
 Right
– same idea but all rows from right table
 Full
– all rows from both tables; not supported in Access
Left Outer Join
Basic SQL 92 Syntax:
SELECT column-list
FROM table1
LEFT JOIN table2
ON join-condition

22
Left Outer Join
(Right click on relationship to edit)
Left Outer Join
 Modify your prior inner join to
use a left join
 Save as qryLeft_Admit
 Now run both the inner and
left joins
 What is the difference?

23
Left Outer Join Results
Subqueries
 One select statement embedded in another
 Can be nested multiple levels deep
 In Access query designer can be placed in
criteria row or field row

24
Multi-valued Subquery
 A type of subquery that compares to a list
 Ex: find all diagnostic codes with no admissions
 Commonly encountered in commercial practice
Multi-valued Subquery
 Place subquery in criteria row

25
Multi-valued Subquery Result
No one was ever admitted with these diagnoses.
Single-valued Subquery
Subquery that returns a single value
Find all admissions with stays greater than the average stay

26
Single-valued Subquery
Subquery that returns a single value
Single-valued Subquery Result

27
Queries using Queries
 Queries can be read just like a table
 Some are updateable
 Using a query as a source for another query
very common in Access – especially for
complicated queries
 In a “back end” database such as Oracle or
SQL Sever you would use a View
Queries using Queries
Filter the prior query ( a little on the complicated side)
for the year 2001

28
Queries using Queries Result
AIN102
Access Query Design
Part 3 – Unions, Action Queries
D. H. D’Urso and Associates
949-489-1472

29
Special Queries
 Most are “Action Queries”
 Reached through Query pull-down menu
Special Queries
 Special action queries have distinct symbols

30
Admissions Database
Diagram of the database for reference in part 3
Data Modification Queries
SQL Action Query
INSERT Append
UPDATE Update
DELETE Delete
SELECT…INTO Maketable

31
Creating Action Queries
 First set up the select query based on the
table you are selecting from
 Test select query
 Then convert to action query
 When you run an action query there is no
result displayed – must look at the
affected table to see the result
Select Into…Maketable
 Creates a new table “on the fly”

32
Select Into…Maketable
New table
Existing table
Make Table
Archived Labor History

33
Delete SQL
 Deletes one or more rows
Basic Syntax:
DELETE FROM table-name
WHERE filter-criteria
Delete
Example:
Delete all
archived
records
newer than
12/31/2001

34
Delete SQL
Example: Delete all archived
admissions_history newer than 12/31/01
Archive after DELETE

35
More complex DELETE with FROM
clause
 Can delete based on matching
records in other tables
 Uses from for criteria instead of
where – uses the matched rows as
an implicit filter condition
 Covered in advanced class
Append Query (SQL Insert)
 Adds new rows to an existing table
 Two forms:
– Single Row
– Multi-Row

36
Single Row Insert
Basic Syntax:
Insert [into] table-name
Values (value-list)
Single Row Insert
Basic Example:
INSERT into xLU_BuildStyle
values(6, “Thick”)
Not really used this way in MS Access. Typical MS
Access use would be Insert…Select as shown in
following slides.

37
Append Query (Multi-row insert)
Multi-row Insert SQL
Basic Syntax:
INSERT [INTO] table-name
SELECT select-statement

38
Multi-row Insert (Append)
Add back archived admissions_history
newer than 12/31/01
Append (Insert) Results

39
Update
 Updates fields in an existing row
Basic Syntax:
UPDATE table-name
SET field1 = new value, field2 = new value,…
WHERE selection-criteria
Update in Query Designer
New value

40
Update
 Increase the admission_history copays by 10%
(unrealistic to change history but we don’t want to step on our
good tables)
Update Results
New values
Remember: you have to look at the affected table.
No “result” is displayed.

41
Unions
 Combines the results of two queries
– Ex: current records and history
 Tables must be union compatible (at least in theory!)
 There is no designer in Access; must be done in SQL view
Union Syntax
SELECT column-list
FROM table1
UNION [ALL]
SELECT same-columns
FROM table2

42
Union Example
Union Result

43
End Session 2
End of Class!
Notes

44
Notes
Notes

Accelerated Computer Training for Working Professionals
Orange Coast Database Associates Course (800)355-9855 or http://ocdatabases.itgo.com
Orange Coast
Database Associates
Specializing in Microsoft Office,
Access, SQL, and related technologies
Computer Training, Programming & Consulting
32422 Alipaz St., Suite A-15
San Juan Capistrano, CA
(800)355-9855 (Toll Free) | (949)489-1472 (Direct) | (949)485-6284 (Fax)
http://www.dhdursoassociates.com | sales@dhdursoassociates.com
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