Download CF and Stored Procedures

CF and Stored Procedures
Lei Wang
ALP International
Main Topics
 Database Locks
 How Cold Fusion perform DB locks
 Stored Procedure
 Stress test to compare Cftransaction
and stored procedure
 How to use stored procedure
 Common Mistakes
Database Locks
 “Lost update problem”
 Multiple users accessing the same data
User1
User2
Read from database
Update record
Update record
Database Locks
 Blocking access for all other users
User1
User2
Begin Transaction
Read Value
Lock
Waiting
Update Value
Commit Transaction
Begin Transaction
Lock
Read Value
Update Value
Commit Transaction
Types of Locks
 Table-level: supported by all database.
The entire table is locked when a user
is posting a transaction that utilizes a
row from that table
 Row-level: supported by higher-end
database. Only records being utilized by
a transaction are locked.
How Cold Fusion perform DB
Locks
 Use CFTRANSACTION to group
multiple queries into a single unit.
CFTRANSACTION also provides
commit and rollback processing.

<CFTRANSACTION>
ACTION="BEGIN" or "COMMIT" or "ROLLBACK"
ISOLATION="Read_Uncommitted" or "Read_Committed" or
"Repeatable_Read"
</CFTRANSACTION>
 CFLOCK
Standard usage of
cftransaction(from CF Studio)

<CFTRY>
<CFSET commitIt = "Yes">
<CFTRANSACTION ACTION="BEGIN">
<CFQUERY NAME='makeNewCourse' DATASOURCE='cfsnippets'>
INSERT INTO Courses (Number, Descript) VALUES ('#myNumber#', '#myDescription#')
</CFQUERY>
<CFCATCH TYPE="DATABASE">
<CFTRANSACTION ACTION="ROLLBACK"/>
<CFSET commitIt = "No">
</CFCATCH>
<CFIF commitIt>
<CFTRANSACTION ACTION="COMMIT"/>
<CFQUERY >
………………………………………
</CFQUERY>
</CFTRANSACTION>
</CFTRY>
Ending tag within the cftry block should be a cfcatch tag
Standard usage of
cftransaction

<CFTRANSACTION ACTION=“BEGIN”>
<CFTRY>
<CFQUERY NAME='makeNewCourse' DATASOURCE='cfsnippets'>
INSERT INTO Courses (Number, Descript) VALUES ('#myNumber#', '#myDescription#')
</CFQUERY>
<CFQUERY >
………………………………………
</CFQUERY>
<CFTRANSACTION ACTION="COMMIT"/>
<CFCATCH TYPE="DATABASE">
<CFTRANSACTION ACTION="ROLLBACK"/>
</CFCATCH>
</CFTRY>
</CFTRANSACTION>
How DB tools perform Lock
 Transaction
A logical unit of work.
 Begin the transaction
 Commit the transaction or rollback
transaction
Standard usage of transaction
 BEGIN TRANSACTION MyTransaction
SELECT * FROM roysched
WHERE title_id LIKE ‘Pc%’
UPDATE roysched
SET royalty = royalty * 1.10
WHERE title_id LIKE 'Pc%'
COMMIT TRANSACTION MyTransaction
Stored Procedure
 A stored procedure is basically a
precompiled program that is stored at
the server site.
 Stored procedure is not written in SQL
PL/SQL
Oracle
Transact-SQL
Sybase & SQL Server
Advantage of Stored
Procedure
 It enables you to write and maintain a
single set of code that is utilized by all
current and future applications that
utilize the database
 It insulates the application developers
from the structure of the database
 It can provide better performance.
Stress test
 LoadRunner is used to conduct 3 levels of




stress test, 10, 50, 100 users.
Internal network 100 M bps
Cold Fusion server 5 on Windows 2000
server (1.5 Ghz CPU, 512 MB memory)
SQL server 7 on the same Windows 2000
server
5 Pentium 430 Mhz Dell machines as client
Stress test results
 Users cftransaction Stored Procedure
1
10
50
100
0.11
1.96
8.15
15
0.11
1.47
4.57
9
What determines which tool to
use
 Less traffic, simple web page
CFTRSACTION
 Heavy traffic, complicated web pages
Stored procedure
How to write stored procedure

CREATE PROCEDURE Insert_invoice
@Amount smallmoney,@DiscAmt smallmoney,@DiscCode char(3),@PaymentTypeCode char(2),
@Token varchar(30),
@NextbContactID int ,@NextInvoiceID int output

AS
 BEGIN TRANSACTION
select
Insert
values(
@NextInvoiceID=ISNULL(max(InvoiceID)+1,10000) from T_Invoice
into T_Invoice
@NextInvoiceID,getdate(),@Amount,@DiscAmt,@DiscCode,@PaymentTypeCode,
null,getdate(),@NextbContactID,null,@Token,'N',null,null)

IF @@ERROR <>0
 ROLLBACK TRANSACTION
 ELSE
 COMMIT TRANSACTION
How to use stored procedure
 Cfstoredproc tag
<CFSTOREDPROC
PROCEDURE="procedure name"
DATASOURCE="ds_name"
USERNAME="username"
PASSWORD="password"
DBSERVER="dbms"
DBNAME="database name"
BLOCKFACTOR="blocksize"
PROVIDER="COMProvider"
PROVIDERDSN="datasource"
DEBUG="Yes/No"
RETURNCODE="Yes/No">
How to user Stored Procedure
 Cfprocparam tag
<CFPROCPARAM
TYPE="IN/OUT/INOUT"
VARIABLE="variable name"
DBVARNAME="DB variable name"
VALUE="parameter value“
CFSQLTYPE="parameter datatype“
MAXLENGTH="length"
SCALE="decimal places"
NULL="yes/no">
CFPROCPARAM
 Type:
IN/OUT/INOUT
 CFSQLTYPE 17 total
CF_SQL_INTEGER
CF_SQL_CHAR
CF_SQL_VARCHAR
CF_SQL_DATE
CF_SQL_MONEY
CFPROCPARAM
 DBVARNAME
Start with @
@NextInvoiceID
 VARIABLE
CF variable name
How to use Stored Procedure
<cfstoredproc datasource="#request.DSN#"
procedure="Insert_Invoice">
<cfprocparam type="in"
cfsqltype="CF_SQL_MONEY"
value="#attributes.Total_Due#" dbvarname="@Amount">
<cfprocparam type="in"
cfsqltype="CF_SQL_MONEY" value="#attributes.DiscAmt#"
dbvarname="@DiscAmt">
<cfprocparam type="in"
cfsqltype="CF_SQL_CHAR"
value="#attributes.assumedDiscount#" dbvarname="@DiscCode">
<cfprocparam type="in"
cfsqltype="CF_SQL_CHAR"
value="#attributes.PaymentType#" dbvarname="@PaymentTypeCode">
<cfprocparam type="in"
cfsqltype="CF_SQL_VARCHAR"
value="#str_customerToken#" dbvarname="@Token">
<cfprocparam type="in" cfsqltype="CF_SQL_INTEGER" value="1"
dbvarname="@NextContactID">
<cfprocparam type="out" cfsqltype="CF_SQL_INTEGER" variable="NextInvoiceID"
dbvarname="@NextInvoiceID">
</cfstoredproc>
Common mistakes when
using Stored Procedure
 Declaration order in stored procedure is
different from CFPROCPARAM order
Error message
Operand type clash: int is incompatible
with text
Variables are not in the same
order
@Amount smallmoney,
@DiscAmt smallmoney,
@DiscCode char(3),
@PaymentTypeCode char(2),
@Token varchar(30),
@NextContactID int,
@NextInvoiceID int output
<cfprocparam type="in"
cfsqltype="CF_SQL_MONEY"
value="#attributes.Total_Due#"
dbvarname="@Amount">
<cfprocparam ***
dbvarname="@DiscAmt">
<cfprocparam ***
dbvarname="@DiscCode">
<cfprocparam ***
dbvarname="@PaymentTypeCod
e">
<cfprocparam *** dbvarname="@Token">
<cfprocparam ***
dbvarname="@NextContactID">
<cfprocparam ***
dbvarname="@NextInvoiceID">
Common Mistakes
 Every In variable need a value
create procedure Update_Email
@StudentID int, @InvoiceID int, @Email varchar(60)
as
Begin
SELECT
FROM
WHERE
@InvoiceID=InvoiceID,@Email=StudentEmail
T_Student
StudentID=@StudentID
UPDATE
T_Invoice
SET
WHERE
END
Email=@Email
InvoiceID=@InvoiceID
Every Variable need a value

<cfprocparam type="in" cfsqltype="CF_SQL_INTEGER"
value="#attributes.StudentID#" dbvarname="@StudentID">
<cfprocparam type="in" cfsqltype="CF_SQL_INTEGER"
value="#attributes.InvoiceID#" dbvarname="@InvoiceID">
<cfprocparam type="in" cfsqltype="CF_SQL_VARCHAR"
value=“[email protected]” dbvarname="@Email">
Conflict with other DB tools
 CFTRANSACTION and TRIGGER
Triggers are specialized stored
procedures that are executed
automatically when a particular event
occurs and are used to enforce data
integrity
A lot of triggers have Rollback
transaction command
Trigger

CREATE TRIGGER Insert_T_Contacts
ON T_Contacts
FOR INSERT AS
DECLARE @JustInsertedpEmail varchar(60),
@ContactIDNew int,
@ContactIDOld int,
BEGIN
SELECT
@JustInsertedpEmail=PrimaryEmailAddress,
@ContactIDNew=ContactID
FROM
INSERTED
SELECT
@ContactIDOld=ContactID,
FROM
T_Contacts
WHERE
PrimaryEmailAddress=@JustInsertedpEmail
AND
ContactID!=@ContactIDNew
IF @@ROWCOUNT > 0
ROLLBACK TRANSACTION
End
Q&A
 [email protected]