MySQL forbinder samme tabel to gange i samme kolonne med en anden værdi, der kun returnerer den seneste række

Prøv

SELECT i.id,  
       i.address, 
       i.status,
       p.max_date contract_date, 
       p.basis_value contract_price, 
       e.max_date estimate_date, 
       e.basis_value estimate_value
  FROM Instructions i LEFT JOIN
(
    SELECT q1.instruction_id, max_date, basis_value
      FROM Estimates e JOIN
    (
        SELECT instruction_id, MAX(basis_date) max_date
          FROM Estimates
         WHERE basis = 'CustomerEstimate'
         GROUP BY instruction_id
    ) q1 ON e.instruction_id = q1.instruction_id AND e.basis_date = q1.max_date
) e ON i.id = e.instruction_id LEFT JOIN
(
    SELECT q2.instruction_id, max_date, basis_value
      FROM Estimates e JOIN
    (
        SELECT instruction_id, MAX(basis_date) max_date
          FROM Estimates
         WHERE basis = 'ContractPrice'
         GROUP BY instruction_id
    ) q2 ON e.instruction_id = q2.instruction_id AND e.basis_date = q2.max_date
) p ON i.id = p.instruction_id

Output:

| ID | ADRESSE | STATUS | CONTRACT_PRICE | CONTRACT_DATE | ESTIMATE_VALUE | ESTIMATE_DATE |------------------------------------------------ -------------------------------------------------- --------------------------| 1 | 27 TAYLOR ROAD, ALBION PARK NSW 2527 | Igangværende | 140.000 | 03-01-2013 | 145000 | 2013-02-09 |

Her er SQLFiddle demo.