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

Read from database

Update record

Update record

User1 User2

Database Locks

Blocking access for all other usersUser1 User2

Begin Transaction

Commit Transaction

Begin Transaction

Commit Transaction

LockRead Value

Update Value

Lock Read Value

Update Value

Waiting

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 MyTransactionSELECT * 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 0.11 0.11

10 1.96 1.47

50 8.15 4.57

100 15 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 @NextInvoiceID=ISNULL(max(InvoiceID)+1,10000) from T_Invoice

Insert into T_Invoice

values(

@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

DBVARNAMEStart 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 orderError messageOperand 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="@PaymentTypeCode">

<cfprocparam *** dbvarname="@Token"><cfprocparam ***

dbvarname="@NextContactID"><cfprocparam ***

dbvarname="@NextInvoiceID">

Common Mistakes

Every In variable need a valuecreate procedure Update_Email

@StudentID int, @InvoiceID int, @Email varchar(60)asBegin

SELECT @InvoiceID=InvoiceID,@Email=StudentEmailFROM T_StudentWHERE StudentID=@StudentID

UPDATE T_Invoice

SET Email=@EmailWHERE InvoiceID=@InvoiceID

END

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=“no@not.com” dbvarname="@Email">

Conflict with other DB tools

CFTRANSACTION and TRIGGERTriggers are specialized stored procedures that are executed automatically when a particular event occurs and are used to enforce data integrityA lot of triggers have Rollback transaction command

Trigger CREATE TRIGGER Insert_T_ContactsON T_Contacts

FOR INSERT AS DECLARE @JustInsertedpEmail varchar(60),@ContactIDNew int, @ContactIDOld int,

BEGINSELECT @JustInsertedpEmail=PrimaryEmailAddress,

@ContactIDNew=ContactIDFROM INSERTEDSELECT @ContactIDOld=ContactID,FROM T_ContactsWHERE PrimaryEmailAddress=@JustInsertedpEmailAND ContactID!=@ContactIDNewIF @@ROWCOUNT > 0ROLLBACK TRANSACTION

End

Q & A

Lwang@alpi.com