substring和 DATE_FORMAT截取年，月

SELECT
    x.core_enterprise_id,
    x.years,
    x.months,
    SUM( x.invoice_amount ),
    SUM( x.invoice_tax_amount ),
    SUM( x.total_amount ) ,
x.invoice_date
FROM
    (
    SELECT
        a.core_enterprise_id,
        a.account_receivable,
        b.pay_id,
        b.invoice_amount,
        b.invoice_tax_amount,
        b.total_amount,
        b.invoice_date,
        substring( DATE_FORMAT( b.invoice_date, '%Y%m' ), 5 ) months,
        DATE_FORMAT( b.invoice_date, '%Y' ) years 
    FROM
        biz_pay_billing_info b,
        biz_pay_comfirm_info a 
    WHERE
        b.sys_status = 1 
        AND b.pay_id = a.uuid 
        AND a.sys_status = 1 
    ) x 
  WHERE 
   1= 1 
   AND x.months = 01 
   AND x.core_enterprise_id='c1003'
GROUP BY
    x.core_enterprise_id,
    x.months,
    x.years;