在sql server中，要求在一个10000条医院就诊记录中，将两个月内出现6次的和六个月出现8次的病人输出到单独的两个表格中。求算法

create table JZJL
(
JZ_TIME  DATETIME,---就诊时间
JZ_NAME VARCHAR(20)---病人名称
)

INSERT INTO JZJL VALUES('20110101','A')
INSERT INTO JZJL VALUES('20110201','A')
INSERT INTO JZJL VALUES('20110101','A')
INSERT INTO JZJL VALUES('20110101','A')
INSERT INTO JZJL VALUES('20110101','A')
INSERT INTO JZJL VALUES('20110101','A')
INSERT INTO JZJL VALUES('20110501','B')
INSERT INTO JZJL VALUES('20110601','B')
INSERT INTO JZJL VALUES('20110601','B')
INSERT INTO JZJL VALUES('20110601','B')
INSERT INTO JZJL VALUES('20110601','B')
INSERT INTO JZJL VALUES('20110601','B')
INSERT INTO JZJL VALUES('20110601','A')
INSERT INTO JZJL VALUES('20110601','A')




 /*两个月出现6次*/

 SELECT T.JZ_NAME FROM

 (SELECT MAX(JZ_TIME) MINTIME,MIN(JZ_TIME) MAXTIME,JZ_NAME FROM JZJL

 WHERE JZ_NAME IN (SELECT JZ_NAME FROM JZJL GROUP BY JZ_NAME HAVING COUNT(1)=6)

 GROUP BY JZ_NAME)T  WHERE DATEDIFF(MONTH,T.MINTIME,T.MAXTIME)<2


 /*6个月出现8次*/
  SELECT T.JZ_NAME FROM

 (SELECT MAX(JZ_TIME) MINTIME,MIN(JZ_TIME) MAXTIME,JZ_NAME FROM JZJL

 WHERE JZ_NAME IN (SELECT JZ_NAME FROM JZJL GROUP BY JZ_NAME HAVING COUNT(1)=8)

 GROUP BY JZ_NAME)T  WHERE DATEDIFF(MONTH,T.MINTIME,T.MAXTIME)<6

create database PatientAdmissions
go

use PatientAdmissions
create table PatientAdmissionsData
(TreatmentID  int NOT NULL PRIMARY KEY
, NI int not null
, Gender varchar(1) not null
, AdmissionDate date not null
, AdmissionType VARCHAR(20) NOT NULL
, Treatment varchar(20) not null
)

BULK INSERT PatientAdmissionsData
FROM 'C:\Users\20021939\Desktop\04062012\PatientAdmissionsData10k.csv'
WITH (
FIELDTERMINATOR = ',',
ROWTERMINATOR = '\n'
)
GO

alter table PatientAdmissionsData add Flag int

select * from PatientAdmissionsData


/*2个月出现6次以及以上*/
SELECT NI FROM
(SELECT MAX(AdmissionDate) MINTIME,MIN(AdmissionDate) MAXTIME,NI FROM PatientAdmissionsData
WHERE NI IN (SELECT NI FROM PatientAdmissionsData GROUP BY NI HAVING COUNT(1)>=6)
GROUP BY NI)T  WHERE DATEDIFF(MONTH,T.MINTIME,T.MAXTIME)<2

/*6个月出现8次以及以上*/
  SELECT NI FROM
(SELECT MAX(AdmissionDate) MINTIME,MIN(AdmissionDate) MAXTIME,NI FROM PatientAdmissionsData
WHERE NI IN (SELECT NI FROM PatientAdmissionsData GROUP BY NI HAVING COUNT(1)>=8)
GROUP BY NI)T  WHERE DATEDIFF(MONTH,T.MINTIME,T.MAXTIME)<6

SELECT AdmissionDate FROM PatientAdmissionsData
WHERE NI= 18