creating a .rdlc report with more than one xsd

i have 4 tables & 4 datasets(xsd files)

iin web application used .rdlc reports
if i am having only one data source in the report its wroking fine with each filed expression a sfollows
=Fields!deptid.Value
all the records of the associated table as displayed

but if i need to display records from multiplle datasets on a single report i have problem
only the first recods get s displayed multiple no of times
=First(Fields!deptid.Value, "PR_OPL")



without using first & using multiple datasource how can i dislay all records

as i need to using more than one table the reports

its nota sub report



sql= " Select deptname ,* from employee,dept where employee.deptid = dept.deptid";


i have 4 tables & 4 datasets(xsd files)

in report1 i need records from 2 tables using join

xsd1= employee

fields = name, add, deptid

xsd2 = dept

fields = deptid, deptname

and how do i design the report from xsd as with single xsd for report 1 i can jsut drag drop the fields but for 2 xsd it gives some aggregate field error