Search2 with multiple joins and where clause - acumatica

Question

I am new to Acumatica and I have syntax errors in the code and can't seem to find them.
Here are the errors and the code.
Building directory '\WebSiteValidationDomain\App_RuntimeCode\'.
\App_RuntimeCode\ContractMaint.cs(13): error CS0305: Using the generic type 'InnerJoin' requires 2 type arguments
\App_RuntimeCode\ContractMaint.cs(13): error CS0305: Using the generic type 'InnerJoin' requires 2 type arguments
[PXMergeAttributes(Method = MergeMethod.Merge)]
[PXDefault(typeof(Search2<PX.Objects.CR.Location.cSiteID,
InnerJoin<PX.Objects.CR.BAccount, On<PX.Objects.CR.BAccount.acctCD, Equal<Current<XRBContrHdr.customerID>>>,
InnerJoin<PX.Objects.AR.Customer, On<PX.Objects.AR.Customer.bAccountID, Equal<PX.Objects.CR.BAccount.bAccountID>>>,
InnerJoin<PX.Objects.CR.Location, On<PX.Objects.CR.Location.bAccountID, Equal<PX.Objects.AR.Customer.bAccountID>>>>,
Where <PX.Objects.CR.BAccount.acctCD, Equal<Current<XRBContrHdr.customerID>>>>), PersistingCheck = PXPersistingCheck.Nothing)]
[PXFormula(typeof(Default<PX.Objects.CR.Location.cSiteID> ))]
protected virtual void XRBContrHdr_DestSiteID_CacheAttached(PXCache cache)
{
}```

Answer 1

The following version of the BQL works correctly:
I have simplified the objects by adding the PX.Objects.xx libraries at the top of the namespace
using PX.Objects.CR;
using PX.Objects.AR;
...
[PXMergeAttributes(Method = MergeMethod.Merge)]
[PXDefault(typeof(Search2<Location.cSiteID,
InnerJoin<BAccount,
On<BAccount.acctCD, Equal<Current<XRBContrHdr.customerID>>>,
InnerJoin<Customer,
On<Customer.bAccountID, Equal<BAccount.bAccountID>>,
InnerJoin<Location,
On<Location.bAccountID, Equal<Customer.bAccountID>>>>>,
Where<BAccount.acctCD, Equal<Current<XRBContrHdr.customerID>>>>), PersistingCheck = PXPersistingCheck.Nothing)]
[PXFormula(typeof(Default<PX.Objects.CR.Location.cSiteID>))]
protected virtual void XRBContrHdr_DestSiteID_CacheAttached(PXCache cache)
{
}
I would recommend that - if possible - you should create these queries in Visual Studio first as it helps tremendously in the process.
About the query:
Your first join is with Baccount.AcctCD: ideally, you should store the integer value in XRBContrHdr.customerID, instead of the CD value. You will notice this pattern in all acumatica pages. With this change, the join would be done with baccount.bAccountID
You are using Current<> in the clause of the first join: if you are using Current for filtering criteria, I would recommend moving it to the Where section.
2.2: The ON clause in the first join between BAccount and Location seems to be missing
No need to add Location in the last Join again. You already have it at that moment.
Try this alternative version:
[PXDefault(typeof(Search2<Location.cSiteID,
InnerJoin<BAccount,
On<BAccount.bAccountID, Equal<Location.bAccountID>>,
InnerJoin<Customer,
On<Customer.bAccountID, Equal<BAccount.bAccountID>>>>,
Where<BAccount.bAccountID, Equal<Current<XRBContrHdr.customerID>>>>), PersistingCheck = PXPersistingCheck.Nothing)]
Notice that both versions will generate multiplicity. There is a 1-to-many relation between BAccount/Customer and Location