Monday, January 12, 2009

Turning Off and On Identity Column in SQL Server

I have been moving over the data from one database to another and am currently using XML files as an intermediate step. The process has been going very smoothly, and I just learned something new. I need to keep certain ID column values across the database and was worried about turning on and off identity column AND automating the XML to DB scripting. But, found a great solutions.

SET IDENTITY_INSERT tablename ON
SET IDENTITY_INSERT tablename OFF

It's wicked cool. But, it actually took me a bit to debug. I had the ON/OFF confused. I thought they were referring to the DB's insert functionality, and so, I thought I had to turn it OFF in order to insert my own values. I realize now, that it is referring to the SQL statements ability to insert identity column value, and hence, I need to turn it ON to run my scripts.

It all comes together rather nicely:

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<!--- Update the data records. --->
<cfquery name="qTurnOnInsert" datasource="#DATA.Source#" username="#DATA.Username#" password="#DATA.Password#">
<!--- Delete the data in the table. --->
DELETE FROM
[#strTableName#]
;


<!--- Turn on the ability insert the identity column. --->
SET IDENTITY_INSERT [#strTableName#] ON
;
</cfquery>


<!--- Loop over the data query to add new rows. --->
<cfloop query="qData">
<!--- Inser this row. --->
<cfquery name="qInsert" datasource="#DATA.Source#" username="#DATA.Username#" password="#DATA.Password#">
INSERT INTO [#strTableName#]
(
<cfloop index="intColumn" from="1" to="#ListLen(qData.ColumnList)#" step="1">
<cfif (intColumn GT 1)>,</cfif>
[#ListGetAt( qData.ColumnList, intColumn )#]
</cfloop>
) VALUES (
<cfloop index="intColumn" from="1" to="#ListLen(qData.ColumnList)#" step="1">
<cfif (intColumn GT 1)>,</cfif>
<cfqueryparam value="#qData['#ListGetAt( qData.ColumnList, intColumn )#'][qData.CurrentRow]#" cfsqltype="CF_SQL_VARCHAR" />
</cfloop>
)
;
</cfquery>
</cfloop>


<!--- Turn off the ability insert the identity column. --->
<cfquery name="qTurnOffInsert" datasource="#DATA.Source#" username="#DATA.Username#" password="#DATA.Password#">
SET IDENTITY_INSERT [#strTableName#] OFF;
</cfquery>

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