1. Kurtis D. Leatham KDL@KomputerMan.com http://www.KomputerMan.com
Databases & SQL Basics
Kurtis D. Leatham

2. About Me
I own KomputerMan.com, a 1 employee Cold Fusion and Flex application development consulting company.
Developing CF applications since 1998 and have been consulting since 1999.
Developed my first Flex App this year.
I am not one of those people who delves into how CF does its magic.
I am much more concerned with how I can use CF to make my own magic!
June 27th- 30th 2007

3. Introduction Database access is easy with CF
Just need to learn a few basics about databases, SQL, and some CF
Some CF experience is presumed, not critical
Most of the CF used is easy to pick up
Some old school some new school
Many topics are not CF specific
May apply to any DBMS
All examples work with MS Access and CF and are available for download.
June 27th- 30th 2007

4. Today’s Agenda Databases, SQL Basics, and ColdFusion
Working with Databases in CF
Databases, Datasources, CFC's
Database basics
CF and SQL Basics
Creating queries
Build dynamic SQL statements
Displaying query results
Interact with a database
CF Forms and SQL
Insert and select data with a CF Form
Q&A
June 27th- 30th 2007

5. DB Management Systems DBMS A DBMS is software that organizes databases
Jill
Jack
Pets
DBMS
CFML Server
A DBMS is software that organizes databases
Access is both a DBMS and a database
Doesn't have to run on the CF server
Databases are the heart of business apps
Either you have one, or will create one
Creating databases is beyond scope of class
June 27th- 30th 2007

6. DB Management Systems
Jill
Jack
CFML Server
SQL
Data
Pets
ODBC Drivers communicate with DB via SQL commands
CF uses “Datasources” to refer to the ODBC Drivers
SQL stands for Structured Query Language
June 27th- 30th 2007

7. Database Basics
Pets
PetTypes
People 2 1
PeoCnt (Identity)
Jack
Frost
12/31/1848
Santa
Clause
BirthDate (Date)
FName (Text 20)
LName (Text 30)
11/24/1863
A Database is a collection of data, hopefully stored in an organized fashion
Composed of tables
Tables are organized in rows and columns
Each column is assigned a Datatype to define the type of data that the column can hold
Datatype examples: text, date, currency, etc…
Each Row contains data
June 27th- 30th 2007

8. Database Basics 2 1
PeoCnt (Identity)
People
Jack
Frost
12/31/1848
Santa
Clause
BirthDate (Date)
FName (Text 20)
LName (Text 30)
11/24/1863
Pets
PetTypes
Tables are Similar to a spreadsheet but a Table IS NOT a spreadsheet
Tables should describe one thing and one thing ONLY
I.E. A persons name, address, birth date, etc…
Not a persons name and the name of their dog(s)
June 27th- 30th 2007

9. Primary Keys 2 1
PeoCnt (Identity)
People
Jack
Frost
12/31/1848
Santa
Clause
BirthDate (Date)
FName (Text 20)
LName (Text 30)
11/24/1863
Each row in the table should be uniquely identified with a Primary Key (PK)
A PK is not required, but I won't build a table without one
Recommendation: Use an Auto Incrementing field as your PK
Concatenated (two or more fields together) Keys work but are a pain!!!
June 27th- 30th 2007

10. Primary Keys No two rows can have the same primary key value
Each row must have a primary key value (no nulls)
Null: Column having no value at all
Not the same as space or empty string
June 27th- 30th 2007

11. Our Example Database
Simple application that tracks people and their pets
One person can have multiple pets
One pet can only be associated to one person (my business rule here)
Each pet must have a type such as Dog or Cat
June 27th- 30th 2007

12. Our Example Database PeoCnt is the PK for the People table
PeoCnt is a Foreign Key in the Pets Table
PetCnt is the PK for the Pets table
PetTypeCnt is the PK for the PetTypes table
PetTypeCnt is a Foreign Key in the Pets table
June 27th- 30th 2007

13. Datasources A Datasource is the CF name for the DB
Pets
DBMS: MS Access DB Name: Pets Filename: Pets.mdb Datasource Name: Pets_DB
A Datasource is the CF name for the DB
Describes the name, physical location, and ODBC driver for connecting to DB
Can choose any name, unique to CF Server
June 27th- 30th 2007

14. Datasources Defined and Created by the CF Admin
Can use OBDC driver or CF JDBC Drivers
Various parameters can be set, to affect performance and features
Can store the username and password
SQL operations can be restricted (read only)
BLOBs can be enabled
See CF Administrator manual for details
June 27th- 30th 2007

15. Datasources Use CF Administrator to create the 'Pets_DB' DSN
In CF Admin click on Data & Services
Click on Data Sources
Fill in the blanks then hit the Add button
June 27th- 30th 2007

16. Datasources Locate the database Hit the Submit button
June 27th- 30th 2007

17. Selecting Data with SQL
The SELECT query is most frequently used query
Retrieves data from one or more tables
But only 1 datasource
At a minimum a SELECT query takes two clauses
The data to be retrieved (SELECT clause)
The table where the data resides (FROM clause)
May also specify
Filtering conditions (WHERE clause)
Sort order (ORDER BY clause)
Can use Joins to link tables together (JOIN or WHERE clause)
June 27th- 30th 2007

18. Simple Select Statement
SELECT FName, LName, City FROM People
Example 1
Specify the columns to be retrieved
Must specify at least one column
Can retrieve all columns in a table with SELECT *
Recommendation:Specify the needed columns
Some databases may require table names to be fully qualified with a prefix indicating the table name
People.FName
June 27th- 30th 2007

19. Datasources Part II <CFQUERY> used to create queries
<CFQUERY DATASOURCE=“Pets_DB” NAME=“GetPeople”> SELECT FName, LName, City FROM People </CFQUERY>
<CFQUERY> used to create queries
DATASOURCE indicates the DSN to use
NAME provides a name for the record set that you will be using somewhere else in your code
Can pass any SQL that’s acceptable to the DBMS inside the CFQUERY Tags
DSN contains Username and Password to connect to the database if needed
June 27th- 30th 2007

20. Datasources Part II Set up a Request variable for your DSN
<CFSET Request.DSN = 'Pets_DB'>
As set inside Application.cfc.
<CFQUERY DATASOURCE=“#Request.DSN#” NAME=“GetPeople”> SELECT FName, LName, City FROM People </CFQUERY>
Set up a Request variable for your DSN
The Request variable gets set in Application.cfc
If the Datasource ever changes you just make one change in Application.cfc and you are finished
June 27th- 30th 2007

21. Displaying Query Results
<CFOUTPUT> can be used to display the record set
To show the first record
<CFOUTPUT> #GetPeople.FName[1]#, #GetPeople.LName[1]# </CFOUTPUT>
To show all records of the record set
<CFOUTPUT QUERY="GetPeople"> #FName#, #LName#, #City#<BR> </CFOUTPUT>
June 27th- 30th 2007

22. Selecting Data with AS Can rename (alias) a column using AS
SELECT FName AS MyName, City
FROM People
Example 2
Can rename (alias) a column using AS
Use it to give a shorter name to a long column name
Give a field a meaningful name
The Aliases name is temporary, lasting only for the life of the record set
Useful when a column in the table has a name that would be illegal in CF
I've had to alias fields like '# of Items'
June 27th- 30th 2007

23. Selecting Data with AS
SELECT (LName + ‘, ’ + FName) AS MyName, City FROM People
Example 3
You can concatenate two or more columns together
Syntax is specific to the DBMS so refer to the DBMS documentation
Can perform mathematical calculations on numeric columns
SELECT Name, (Salary * 1.10) AS AdjSalary
June 27th- 30th 2007

24. Selecting Data with WHERE
SELECT FName, LName, PeoCnt FROM People WHERE PeoCnt = 1
Example 4
Can select specific records with a WHERE clause
Find the Person WHERE PeoCnt = 1
You can filter on columns you don’t SELECT
If the datatype of the column in the WHERE clause is numeric, the value is specified without quotes
June 27th- 30th 2007

25. Selecting Data with WHERE
SELECT FName, LName, City FROM People WHERE FName = 'Jack'
Example 5
If the datatype of the column in the WHERE clause is alphanumeric, the value is specified with tick marks
June 27th- 30th 2007

26. Selecting Data with WHERE
SELECT FName, LName, City FROM People WHERE BirthDate <= #CreateODBCDate('01/01/1901')#
Example 6
The WHERE clause can contain dates
Formatted dates varies by DBMS but I've found this format to be pretty universal
Returns the FName, LName, and City of all people born before Jan 1, 1901
Be careful if using date time stamps because the time stamp portion of the field makes the '=' difficult to use
June 27th- 30th 2007

27. Selecting Data with AND or OR
SELECT FName, LName, City FROM People WHERE BirthDate <= #CreateODBCDate('01/01/1901')# AND FName = 'Jack'
SELECT FName, LName, City FROM People WHERE BirthDate <= #CreateODBCDate('01/01/1901')#
OR FName = 'Jack'
Example 7
Can use more than one parameter in your WHERE clauses
Use the AND clause to match both parameters
Use the OR clause to match one of the parameters
June 27th- 30th 2007

28. Selecting Data with IN
SELECT FName, LName, PeoCnt FROM People WHERE PeoCnt IN (1,3,4)
Example 8
Can search for a match on multiple values using the IN clause
Values are separated with commas and are enclosed with parentheses
This performs the equivalent of an “OR” search
WHERE PeoCnt = 1 OR PeoCnt = 3 OR PeoCnt = 4
June 27th- 30th 2007

29. Selecting Data with NOT
SELECT FName, LName, PeoCnt FROM People WHERE PeoCnt NOT IN (3,5,7)
SELECT FName, LName, City FROM People WHERE BirthDate IS NOT NULL
Example 9
To negate a condition, use the NOT operator
June 27th- 30th 2007

30. Selecting Data with LIKE
SELECT FName, LName, City FROM People WHERE FName LIKE ‘J%’
Example 10
Can search for a match of wildcards using the LIKE clause
Finds all FName records beginning with a J
% can be used anywhere in the string
To find records with name containing “ar”, like Charles, Arnold, Barbara, Karen, use
WHERE FName LIKE ‘%ar%’
Beware: wildcard matches are generally the slowest form of filtering
June 27th- 30th 2007

31. Selecting Data With AND
SELECT FName, LName, Pet_Name, TypeOfPet FROM People, Pets, PetTypes WHERE People.PeoCnt = Pets.PeoCnt
AND Pets.PetTypeCnt = PetTypes.PetTypeCnt
Example 11
This query will return all people that have pets and their pets names
This is done using a JOIN
I prefer to use the WHERE clause to make my joins unless I need to use an OUTER join to select all data from one table and only matching records from another table. (Not covered in this session)
June 27th- 30th 2007

32. Ordering Selected Data
SELECT FName, LName, Pet_Name, TypeOfPet FROM People, Pets, PetTypes WHERE People.PeoCnt = Pets.PeoCnt
AND Pets.PetTypeCnt = PetTypes.PetTypeCnt
ORDER BY LName DESC, Pet_Name
Example 12
Use ORDER BY to sort the record set
Can specify multiple, comma-separated columns
Data is sorted by the first column, then by the second column, etc…
Data is sorted in ascending order by default
Force descending order with DESC clause
June 27th- 30th 2007

33. Creating Dynamic Queries
SELECT FName, LName, City FROM People WHERE PeoCnt = #Form.PeoCnt#
SELECT FName, LName, City FROM People WHERE FName = '#Form.FName#'
Example 13
Can search for a match based on Form variables
Alphanumeric variables need tick marks, numeric variables do not
June 27th- 30th 2007

34. Creating Dynamic Queries
SELECT FName, LName, City FROM People WHERE <CFLOOP FROM="1" TO="#ArrayLen(CityArray)#" INDEX="cc">
<CFIF cc EQ 1>City = '#CityArray[cc]#'<CFELSE>
OR City = '#CityArray[cc]#'</CFIF></CFLOOP>
Example 14
CF builds the SQL at run time using conditional statements and variables
Powerful yet easy to use feature of CF
CF processes the CF tags and variables before passing the resulting SQL to the database
June 27th- 30th 2007

35. Creating Dynamic Queries
In this case we take all of the selected City names and place them into an Array called CityArray.
<CFSET CityArray = ListToArray(Form.City)>
You could just loop over the form control itself like a LIST
Look at debug output (<CFDUMP> Works well)
I prefer to dump the form control into an Array, developers choice IMHO
June 27th- 30th 2007

36. INSERT Operations
INSERT INTO People (FName, LName, Address,
City, State, ZipCode) VALUES ('#Form.FName#', '#Form.LName#', '#Form.Address#',
'#FORM.City#', '#Form.State#', '#Form.ZipCode#')
Example 15
The INSERT statement inserts one or more rows into a table
Include all columns that do not permit nulls
Data can be inserted into one table at a time only
INSERT can be tied to Form Controls (SELECT, INPUT, Radio, etc…)
June 27th- 30th 2007

37. UPDATE Operations
UPDATE People SET FName = 'Santa Rockin',
LName = 'My Clause' WHERE PeoCnt = 1
Example 16
The UPDATE statement updates data in one or more rows:
Specify the table to be updated, rows to be affected, and the new values
Can update several columns at once
If no WHERE clause is used, change is made to ALL rows in the table.
Could be disastrous!
Could be intentional
Use caution!!!
June 27th- 30th 2007

38. Quick CFC Overview
Cold Fusion Components were created to assist you in code re-use.
I both like and dislike them
Great for all of your Select statements
I don't use them with Action pages myself, I prefer to have one Action page tied to a Form page
I find them difficult to use while developing because I can't see the fields in the CFC without swapping windows.
Queries are stored in their own CFC template
Queries get 'Called' from the template that needs them
June 27th- 30th 2007

39. Quick CFC Overview Creating a CFC: <CFCOMPONENT name="DropDowns"
hint="Contains methods that expose the drop down list details.">
<CFFUNCTION NAME="GetPetTypes" RETURNTYPE="query" OUTPUT="No"
HINT="Return all of the Pet Types">
<CFARGUMENT NAME="MyPetType" REQUIRED="No" TYPE="string">
<CFSET var QryPetTypes = "">
<CFQUERY NAME="QryPetTypes" DATASOURCE="#Request.dsn#">
SELECT PetTypeCnt, TypeOfPet
FROM PetTypes
<CFIF IsDefined("MyPetType")>WHERE TypeOfPet='#MyPetType#'</CFIF>
</CFQUERY>
<CFRETURN QryPetTypes>
</CFFUNCTION>
</CFCOMPONENT>
June 27th- 30th 2007

40. Quick CFC Overview Calling a CFC:
<CFINVOKE COMPONENT="DropDowns" METHOD="GetPetTypes"
RETURNVARIABLE="QryPetTypes"></CFINVOKE>
<CFOUTPUT QUERY="QryPetTypes">
#PetTypeCnt#, #TypeOfPet#<BR>
</CFOUTPUT>
This template calls DropDowns.cfc because that is where the QryPetTypes query is residing
June 27th- 30th 2007

41. Conclusion Database and SQL processing is easy
CF makes it even easier
Still plenty more for you to learn, I.E.
BLOCKFACTOR
CACHEDWITHIN
<CFQUERYPARAM>
Practice the examples offered here
Download the sample application
June 27th- 30th 2007

42. Q&A ?
June 27th- 30th 2007