Query to get Invoice Number from event id, Number and project number

SELECT distinct rcta.trx_number

into l_invoice_number

FROM ra_customer_trx_all rcta

, ra_customer_trx_lines_all rctla

, pa_draft_invoice_items pdii

, pa_events pe

WHERE 1 = 1

AND rcta.customer_trx_id = rctla.customer_trx_id

AND TO_CHAR (pdii.draft_invoice_num) = rctla.interface_line_attribute2

AND TO_CHAR (pdii.line_num) = LTRIM (rctla.interface_line_attribute6)

AND pdii.event_num = pe.event_num

AND pdii.event_num IS NOT NULL

AND rctla.interface_line_attribute1 = rec_deliverable_action.action_project_number

AND pdii.project_id = rec_deliverable_action.project_id

AND pdii.task_id = rec_deliverable_action.task_id

AND pe.event_id = rec_deliverable_action.event_id;