Oracle not return results only in Oracle11g

Question

Hello everyone.
I have a very strange problem.
I have this query:
SELECT *
  FROM
    (SELECT objT.*,
      UP.UserId permissionUserId,
      UP.ObjectVersionLabel permissionObjectId,
      UP.DocumentAccessPermissions permissionDocAccessPermissions,
      UP.SpecialPermissions permissionSpecialPermissions,
      UP.IsDeleted permissionIsDeleted
    FROM TMPLT_WORKFLOWS objT
    LEFT JOIN
      (SELECT * FROM PERMIT_WORKFLOWS_USERS ut WHERE ut.UserId = 81
      ) UP
    ON objT.VersionLabel = UP.ObjectVersionLabel
    INNER JOIN RELAT_SITES_WORKFLOW_TEMPLATES siteT
    ON objT.VersionLabel     = siteT.ObjectVersionLabel
    WHERE objT.IsDeleted    <> 1
    AND ( UP.UserId = 81 OR UP.UserId IS NULL)
    AND ( UP.IsDeleted      <> 1  OR UP.IsDeleted IS NULL)
    AND objT.IsStoragePolicy = 0
    AND IsCurrent            = 1
    AND siteT.IsDeleted     <> 1
    AND ( siteT.SiteId       = 4  OR siteT.SiteId = -101)
    ) A
WHERE A.TemplateId IN
    SELECT  TemplateId
    FROM TMPLT_WORKFLOWS
    WHERE VersionLabel NOT IN
      (SELECT ObjectVersionLabel
      FROM PERMIT_WORKFLOWS_USERS
      WHERE UserId = 81
      AND SpecialPermissions BETWEEN 12288 AND 16383
      AND IsDeleted = 0)
)when I runs the query on Oracle11G I got no results.
If I runs this query on Oracle10g with the same data I got results.
I started to investigate this and I saw two strange things:
1. If I write 'SELECT To_Number(TemplateId)' instead of 'SELECT TemplateId' in the IN clause everithing works.
2. If I comment out the line: 'AND ( UP.UserId = 81 OR UP.UserId IS NULL)' everything works - For this query UP is empty so this isn't supposed to change the results.
Again, it's happening only on 11g.
What is this?

Answer 1

I created a simple example.
Creation of table CUSTOMERS
--  DDL for Table CUSTOMERS
  CREATE TABLE "TESTS"."CUSTOMERS"
   (     "CUSTOMERLABEL" NVARCHAR2(50),
     "CUSTOMERNAME" NVARCHAR2(255),
     "CUSTOMERID" NUMBER(10,0)
   ) SEGMENT CREATION IMMEDIATE
  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS" ;
--  DDL for Index CUSTOMERS_PK
  CREATE UNIQUE INDEX "TESTS"."CUSTOMERS_PK" ON "TESTS"."CUSTOMERS" ("CUSTOMERID")
  PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS" ;
--  Constraints for Table CUSTOMERS
  ALTER TABLE "TESTS"."CUSTOMERS" ADD CONSTRAINT "CUSTOMERS_PK" PRIMARY KEY ("CUSTOMERID")
  USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255 COMPUTE STATISTICS
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS"  ENABLE;
  ALTER TABLE "TESTS"."CUSTOMERS" MODIFY ("CUSTOMERLABEL" NOT NULL ENABLE);
  ALTER TABLE "TESTS"."CUSTOMERS" MODIFY ("CUSTOMERNAME" NOT NULL ENABLE);
  ALTER TABLE "TESTS"."CUSTOMERS" MODIFY ("CUSTOMERID" NOT NULL ENABLE);Creation of table ORDERS
--  DDL for Table ORDERS
  CREATE TABLE "TESTS"."ORDERS"
   (     "ORDERID" NUMBER(10,0),
     "CUSTOMERLABEL" NVARCHAR2(50),
     "ORDERDETAILS" NVARCHAR2(255)
   ) SEGMENT CREATION IMMEDIATE
  PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS" ;
--  DDL for Index ORDERS_PK
  CREATE UNIQUE INDEX "TESTS"."ORDERS_PK" ON "TESTS"."ORDERS" ("ORDERID")
  PCTFREE 10 INITRANS 2 MAXTRANS 255
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS" ;
--  Constraints for Table ORDERS
  ALTER TABLE "TESTS"."ORDERS" ADD CONSTRAINT "ORDERS_PK" PRIMARY KEY ("ORDERID")
  USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULT CELL_FLASH_CACHE DEFAULT)
  TABLESPACE "USERS"  ENABLE;
  ALTER TABLE "TESTS"."ORDERS" MODIFY ("ORDERID" NOT NULL ENABLE);
  ALTER TABLE "TESTS"."ORDERS" MODIFY ("CUSTOMERLABEL" NOT NULL ENABLE);
  ALTER TABLE "TESTS"."ORDERS" MODIFY ("ORDERDETAILS" NOT NULL ENABLE);I inserted two rows to table CUSTOMERS:
CustomerLabel | CustomerName | CustomerId
Label1 | George | 1
Label2 | Tom | 2
I also inserted two rows to table ORDERS:
OrderId| CustomerLabel | OrderDetails
7 | Label1 | Details1
8 | Label1 | Details2
Now, when i runs this simple query I got no results:
SELECT * FROM customers CST
LEFT JOIN (SELECT * FROM orders WHERE orderid = 1) UP
ON CST.CustomerLabel = UP.CustomerLabel
WHERE ( UP.orderid   = 1 OR UP.orderid       IS NULL)
AND CST.customerId IN (SELECT customerId FROM customers)Thank you.