如何计算MySQL中的最大值?

    SELECT 
       DISTINCT(ecode_id)
      ,MAX(eligible_allowance)AS monthlyBudgetAmt
      ,approval_date
    FROM vefm_dailybudget
    WHERE
        division=1 AND region=1
        AND unit=1 AND common_status IN('Finance - II Approved','Cash Disbursement')
        AND eligible_allowance != 0
        AND approval_date BETWEEN ' 2019-02-01'
        AND '2019-02-28' AND budget_type='monthly'
    GROUP BY ecode_id ORDER BY ecode_id

下面是我从上面得到的值,总共91行。我不想显示91行,而是要显示符合条件的津贴的总值。有人能帮忙吗

Ecode ID Eligible Allowance Approval Date
E2404   12000   2019-02-14
E2660   9000    2019-02-19
E2694   10500   2019-02-14
E2739   7500    2019-02-14
E2911   7500    2019-02-14
E2912   7500    2019-02-14
E2929   7500    2019-02-14
E2967   7500    2019-02-14
E3013   7500    2019-02-14
E3100   6000    2019-02-14
E3168   7500    2019-02-14
E3199   7500    2019-02-14
E3225   7500    2019-02-27
E3301   6000    2019-02-14
E3441   6000    2019-02-14
E3451   6000    2019-02-14
E3548   6000    2019-02-22
E3581   6000    2019-02-14
E3602   6000    2019-02-22
E3647   7500    2019-02-02
E3650   6000    2019-02-14
E3684   6000    2019-02-14
E3698   7500    2019-02-14
E3701   6000    2019-02-27
E3703   7500    2019-02-14

我需要以上查询的和值是516000

SELECT SUM(t.monthlyBudgetAmt) AS total FROM ( SELECT MAX(eligible_allowance) AS monthlyBudgetAmt FROM vefm_dailybudget WHERE division=1 AND region=1 AND unit=1 AND common_status IN('Finance - II Approved','Cash Disbursement') AND eligible_allowance != 0 AND approval_date BETWEEN '2019-02-01' AND '2019-02-28' AND budget_type='monthly' GROUP BY ecode_id ) t