Integration from Salesforce to QuickBooks

SELECT Opportunity.Id,Opportunity.AVSFQB__Primary_Contact__r.FirstName,Opportunity.AVSFQB__Primary_Contact__r.LastName,Opportunity.Owner.QB_SalesRep_ID__c,
Opportunity.AVSFQB__Primary_Contact__r.Email,Opportunity.AVSFQB__QuickBooks_Id__c,Opportunity.AccountId,LastModifiedDate,Opportunity.Account.Id,
Opportunity.Account.CurrencyIsoCode,Opportunity.Account.Name,Opportunity.Account.BillingStreet,Opportunity.Account.BillingCity,
Opportunity.Account.BillingState,Opportunity.Account.BillingPostalCode,Opportunity.Account.BillingCountry,Opportunity.Account.ShippingStreet,
Opportunity.Account.ShippingCity,Opportunity.Account.ShippingState,Opportunity.Account.ShippingPostalCode,Opportunity.Account.ShippingCountry,
Opportunity.Account.Fax,Opportunity.Account.Phone,Name,Description,CloseDate ,(SELECT Quantity,UnitPrice,Description,Opportunity.owner.FirstName,
Opportunity.owner.LastName,Opportunity.Id,Opportunity.CloseDate,PricebookEntry.Name,PricebookEntry.Product2.ProductCode,PricebookEntry.Product2.Name,
PricebookEntry.Product2.Description,PricebookEntry.Product2.Id,PricebookEntry.UnitPrice,PricebookEntry.Product2.AVSFQB__QuickBooks_ItemType__c FROM
OpportunityLineItems) ,Opportunity.Account.AVSFQB__QuickBooks_Id__c,Opportunity.AVSFQB__Generate_Object__c FROM Opportunity where
Opportunity.AVSFQB__Generate_Object__c = 'Invoice'
CustomerAddRq/CustomerAdd/CurrencyRef/FullName = IF(VALUE("Account/CurrencyIsoCode").equals("USD"),"US Dollar",IF(VALUE("Account/CurrencyIsoCode").equals("GBP"),"British Pound Sterling",IF(VALUE("Account/CurrencyIsoCode").equals("EUR"),"Euro",IF(VALUE("Account/CurrencyIsoCode").equals("CAD"),"Canadian Dollar",""))))


Add the same mapping to following workflows as well if, you are using these workflows in Integration:

Integration from QuickBooks to Salesforce

IF(VALUE("CustomerRef/FullName/CustomerRet/CurrencyRef/FullName").equals("US Dollar"),
"USD",IF(VALUE("CustomerRef/FullName/CustomerRet/CurrencyRef/FullName").equals("British Pound Sterling"),
"GBP",IF(VALUE("CustomerRef/FullName/CustomerRet/CurrencyRef/FullName").equals("Euro"),
"EUR",IF(VALUE("CustomerRef/FullName/CustomerRet/CurrencyRef/FullName").equals("Canadian Dollar"),"CAD",""))))
IF(VALUE("CustomerRef/FullName/CustomerRet/CurrencyRef/FullName").equals("US Dollar"),
"USD",IF(VALUE("CustomerRef/FullName/CustomerRet/CurrencyRef/FullName").equals("British Pound Sterling"),
"GBP",IF(VALUE("CustomerRef/FullName/CustomerRet/CurrencyRef/FullName").equals("Euro"),
"EUR",IF(VALUE("CustomerRef/FullName/CustomerRet/CurrencyRef/FullName").equals("Canadian Dollar"),"CAD",""))))