sql

    select * from Appointment where yyid in ('2021051100000012','2021051900000018','2021052100000021')
    用以下代替：
    
    select * FROM Appointment  a JOIN (
 select '2021051100000012' yyid  union select '2021051900000018'  UNION  SELECT '2021052100000021' ) b 
  on  a.yyid=b.yyid

select a.* from Appointment a where a.yyid in(select yyid from OrderPayment where ReceivableAmount=3000 )
     用下面的语句替换：
     select a.* from Appointment a where 1=1 and  exists(select 1 from OrderPayment where yyid=a.yyid and ReceivableAmount=3000 )

SELECT
    * 
FROM
    phonebill --取出每月通话费最高和最低的两个地区。
SELECT TOP
    2 * 
FROM
    phonebill 
WHERE
    net_type = 'G' 
GROUP BY
    bill_month 
ORDER BY
    area_code DESC SELECT
    BILL_MONTH,
    AREA_CODE,
    SUM ( LOCAL_FARE ) LOCAL_FARE,
    FIRST_VALUE ( AREA_CODE ) OVER ( PARTITION BY BILL_MONTH ORDER BY SUM ( LOCAL_FARE ) DESC ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING ) FIRSTVAL,
    LAST_VALUE ( AREA_CODE ) OVER ( PARTITION BY BILL_MONTH ORDER BY SUM ( LOCAL_FARE ) DESC ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING ) LASTVAL 
FROM
    phonebill 
GROUP BY
    BILL_MONTH,
    AREA_CODE 
ORDER BY
    BILL_MONTH SELECT
    bill_month,
    area_code,
    SUM ( local_fare ) local_fare,
    first_value ( area_code ) OVER ( partition BY bill_month ORDER BY SUM ( local_fare ) DESC ROWS BETWEEN unbounded preceding AND unbounded following ) firstval,
    last_value ( area_code ) OVER ( partition BY bill_month ORDER BY SUM ( local_fare ) DESC ROWS BETWEEN unbounded preceding AND unbounded following ) lastval 
FROM
    phonebill 
GROUP BY
    bill_month,
    area_code 
ORDER BY
    bill_month SELECT
    bill_month,
    area_code,
    SUM ( local_fare ) local_fare 
FROM
    phonebill a 
GROUP BY
    bill_month,
    area_code 
ORDER BY
    bill_month SUM ( loc_fare )