Ajax checing for duplicte records

Question

i am trying to have a form in ajx that will also insert a new
contact... i havit working with the insert part but i want to have
it check for duplicate records before inserting the contact... here
is the form ... and i also have a cfc for the functions
<cfcomponent output="false">
<cfset this.dsn="myserver">
<!--- Populates the grower list Select --->
<cffunction name="getCompany" access="remote"
returntype="array">
<cfset var rsData="">
<cfset var myReturn=ArrayNew(2)>
<cfset var i=0>
<cfquery name="rsData" datasource="myserver">
SELECT cid ,Company
FROM Contacts
order by Company asc
</cfquery>
<cfloop query="rsData">
<cfset myReturn[rsData.currentrow] [1]=rsdata.cid>
<cfset myReturn[rsData.currentrow] [2]=rsdata.Company>
</cfloop>
<cfreturn myReturn>
</cffunction>
<!--- Populates list related to grower --->
<cffunction name="getcontacts" access="remote"
returntype="array">
<cfargument name="cid" type="string" required="no">
<cfset var rsData="">
<cfset var myReturn=Arraynew(2)>
<cfset var i=0>
<cftry>
<cfquery name="rsdata" datasource="myserver">
SELECT cid, Company, FullName, Lname, Fname, Address1,
Address2, City, State, zip, country, Phone, ext, cell, Fax,
tollfree, Web, Email, Title, ExecutiveTitle
FROM Contacts
WHERE Contacts.Company = '#arguments.cid#'
</cfquery>
<cfcatch type="any">
<cfset returnStruct.success = false />
<cfset returnStruct.message = cfcatch.message />
</cfcatch>
</cftry>
<cfloop query="rsdata">
<cfif rsdata.recordcount gt 0>
<cfset myReturn[rsData.currentrow] [1]=rsdata.cid>
<cfset myReturn[rsData.currentrow] [2]=rsdata.FullName>
<!--- <cfelse>
<cfset rsdata.cid = 999999>
<cfset rsdata.FullName = 'none'>
<cfset myReturn[rsData.currentrow] [1]=rsdata.cid>
<cfset myReturn[rsData.currentrow] [2]=rsdata.FullName>
--->
</cfif>
</cfloop>
<cfreturn myReturn>
</cffunction>
<!--- Gets contact info for 2page
contacts!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
--->
<cffunction name="getcontactsinfo2" access="remote"
returnType="struct">
<cfargument name="growerName" type="string"
required="no">
<cfset var data="">
<cfset var c = "">
<cfset var s = structNew()>
<cftry>
<cfquery name="data" datasource="myserver">
SELECT cid, Company, FullName, Lname, Fname, Address1,
Address2, City, State, zip, country, Phone, ext, cell, Fax,
tollfree, Web, Email, Title, ExecutiveTitle
FROM Contacts
WHERE Company= <cfqueryparam cfsqltype="cf_sql_varcar"
value="#arguments.growerName#">
</cfquery>
<cfloop list="#data.columnlist#" index="c">
<cfset s[c] = data[c][1]>
</cfloop>
<cfcatch type="any">
<cfset returnStruct.success = false />
<cfset returnStruct.message = cfcatch.message />
</cfcatch>
</cftry>
<cfreturn s>
</cffunction>
<cffunction name="getcontactsinfo" access="remote"
returnType="struct">
<cfargument name="cid" type="numeric" required="true">
<cfset var data="">
<cfset var c = "">
<cfset var s = structNew()>
<cftry>
<cfquery name="data" datasource="myserver">
SELECT cid, Company, FullName, Lname, Fname, Address1,
Address2, City, State, zip, country, Phone, ext, cell, Fax,
tollfree, Web, Email, Title, ExecutiveTitle
FROM Contacts
WHERE contacts.cid= <cfqueryparam
cfsqltype="cf_sql_integer" value="#arguments.cid#">
</cfquery>
<!--- --->
<cfloop list="#data.columnlist#" index="c">
<cfset s[c] = data[c][1]>
</cfloop>
<cfcatch type="any">
<cfset returnStruct.success = false />
<cfset returnStruct.message = cfcatch.message />
</cfcatch>
</cftry>
<cfreturn s>
</cffunction>
<!--- Updates the database of grower contacts --->
<cffunction name="markTaskComplete" output="false"
returntype="struct" access="remote" hint="i mark a task
complete">
<cfargument name="cid2" type="numeric" required="true"
/>
<cfargument name="company2" type="string" required="true"
/>
<cfargument name="address2" type="string" required="true"
/>
<cfargument name="city2" type="string" required="true"
/>
<cfargument name="state2" type="string" required="true"
/>
<cfargument name="zip2" type="string" required="true"
/>
<cfset var qMarkTaskComplete = "" />
<cfset var returnStruct = structNew() />
<cfset returnStruct.success = true />
<cfset returnStruct.taskID = arguments.cid2 />
<cftry>
<cfquery name="qMarkTaskComplete"
datasource="myserver">
UPDATE
Contacts
SET
Company = <cfqueryparam value="#arguments.company2#"
cfsqltype="cf_sq_varcar" /> ,
Address1 = <cfqueryparam value="#arguments.address2#"
cfsqltype="cf_sq_varcar" /> ,
City = <cfqueryparam value="#arguments.city2#"
cfsqltype="cf_sq_varcar" />,
State = <cfqueryparam value="#arguments.state2#"
cfsqltype="cf_sq_varcar" />,
zip = <cfqueryparam value="#arguments.zip2#"
cfsqltype="cf_sq_varcar" />
WHERE
cid = <cfqueryparam value="#arguments.cid2#"
cfsqltype="cf_sq_int" />
</cfquery>
<cfcatch type="Database">
<cfset returnStruct.success = false />
<cfset returnStruct.message = cfcatch.message />
</cfcatch>
</cftry>
<cfdump var="#returnStruct#"/>
<cfreturn returnStruct />
</cffunction>
<cffunction name="lookupGrower" access="remote"
returntype="array">
<cfargument name="search" type="any" required="false"
default="">
<!--- Define variables --->
<cfset var data="">
<cfset var result=ArrayNew(1)>
<!--- Do search --->
<cfquery name="data" datasource="myserver">
SELECT cid, Company, FullName, Lname, Fname, Address1,
Address2, City, State, zip, country, Phone, ext, cell, Fax,
tollfree, Web, Email, Title, ExecutiveTitle
FROM Contacts
WHERE (Company LIKE '#ARGUMENTS.search#%')
</cfquery>
<!--- Build result array --->
<cfloop query="data">
<cfset ArrayAppend(result, Company)>
</cfloop>
<!--- And return it --->
<cfreturn result>
</cffunction>
<cffunction name="markTaskComplete2" output="false"
returntype="struct" access="remote" hint="i mark a task
complete">
<cfargument name="company3" type="string" required="true"
/>
<cfargument name="address3" type="string" required="true"
/>
<cfargument name="city3" type="string" required="true"
/>
<cfargument name="state3" type="string" required="true"
/>
<cfargument name="zip3" type="string" required="true"
/>
<cfset var qMarkTaskComplete = "" />
<cfset var returnStruct = structNew() />
<cfset returnStruct.success = true />
<cfset returnStruct.taskID = arguments.cid />
<cftry>
<cfquery name="qMarkTaskComplete"
datasource="myserver">
INSERT INTO KYIntranet.dbo.Contacts
(Company
,Address1
,City
,State
,zip)
VALUES
(<cfqueryparam value="#arguments.company3#"
cfsqltype="cf_sq_varcar" /> , <cfqueryparam
value="#arguments.address3#" cfsqltype="cf_sq_varcar" />
,<cfqueryparam value="#arguments.city3#"
cfsqltype="cf_sq_varcar" />,<cfqueryparam
value="#arguments.state3#" cfsqltype="cf_sq_varcar"
/>,<cfqueryparam value="#arguments.zip3#"
cfsqltype="cf_sq_varcar" />)
</cfquery>
<cfcatch type="any">
<cfset returnStruct.success = false />
<cfset returnStruct.message = cfcatch.message />
</cfcatch>
</cftry>
<cfreturn returnStruct />
</cffunction>
</cfcomponent>

Answer 1

From my understanding your table that gets inserted is
KYIntranet.dbo.Contacts . And i guess company field in that table
needs to be checked for duplicates. So you can put the company
field as primary key for that table. Inserting the same company
name can result in a Primary key exception meaning that a duplicate
has been entered. By this way you can check for duplicates.
<cftry>
<cfquery>Insert SQL code</cfquery>
<cfcatch>
<--Code to handle primary key exception-->
</cfcatch>
<cftry>