从xml插入时如何检查记录是否存在的sql

Question

I am inserting records from some XML. I need to check if the record already exists and insert if it doesn't and update if it does.
This is what i have but there are multiple records returned from the subquery.

   ALTER PROCEDURE [dbo].[InsertOrdersFromXML] (
 @xmlData XML 
 )
 AS
 begin tran /* default read committed isolation level is fine */
declare @orderId int
set @orderId = (SELECT x.XmlCol.value('OrderNumber[1]', 'int') FROM @xmlData.nodes('//Order') AS x(XmlCol))

if not exists (SELECT StoreorderId FROM Orders with (updlock, rowlock, holdlock) where StoreOrderId = @orderId)
    /* insert */

INSERT INTO [dbo].[Orders]
           ([StoreOrderId]
           ,[CustomerId]
           ,[OrderDate]

SELECT
x.XmlCol.value('OrderNumber[1]', 'int') as 'StoreOrderId',
x.XmlCol.value('CustomerID[1]', 'int') as 'CustomerId',
x.XmlCol.value('OrderDate[1]', 'datetime') as ' OrderDate',

FROM @xmlData.nodes('//Order') AS x(XmlCol)

INSERT INTO [dbo].[OrderLines]
           ([OrderId]
           ,[StoreOrderId]
           ,[ProductId]
           ,[Quantity]
           ,[ChosenColour]
           ,[ChosenSize]
           ,[ShoppingCartRecID])

select (select OrderId from Orders with (updlock, rowlock, holdlock) where storeorderid = x.XmlCol2.value('OrderNumber[1]', 'varchar(25)')),

x.XmlCol2.value('OrderNumber[1]', 'varchar(25)') as ' OrderNumber',
    x.XmlCol2.value('ProductID[1]', 'varchar(25)') as ' ProductID',
    x.XmlCol2.value('Quantity[1]', 'varchar(25)') as ' Quantity',
    x.XmlCol2.value('ChosenColor[1]', 'varchar(25)') as ' ChosenColor',
    x.XmlCol2.value('ChosenSize[1]', 'varchar(25)') as ' ChosenSize',
    x.XmlCol2.value('ShoppingCartRecID[1]', 'varchar(25)') as ' ShoppingCartRecID'
    FROM @xmlData.nodes('//Order/OrderItems/Item') AS x(XmlCol2)

commit

also, how can I add the update part?

Answer 1

You can simply do this to insert or update :

if not exists (SELECT StoreorderId FROM Orders with (updlock, rowlock, holdlock) 
               where StoreOrderId = @orderId)
    begin
        /* insert */
    end
else
    begin
        /* update */
    end

With the multiple records you can use a cursor around your insert / update statements, like so:

declare order_cursor cursor for
        SELECT x.XmlCol.value('OrderNumber[1]', 'int') 
        FROM @xmlData.nodes('//Order') AS x(XmlCol)

open order_cursor;
fetch next from order_cursor into @orderId
while @@FETCH_STATUS=0
begin
    if not exists (SELECT StoreorderId 
                   FROM Orders with (updlock, rowlock, holdlock) 
                   WHERE StoreOrderId = @orderId)
        begin
            /* insert */
        end
    else
        begin
            /* update */
        end

    fetch next from order_cursor into @orderId
end
close order_cursor;
deallocate order_cursor; 

Obviously this isn't tested, but it should set up a cursor against your XML , then allocates the @orderId one row at a time to process the rest of the code.