SQL 如何实现类For循环功能

[binghuochanmian]

已知三张表Test_user(员工表), Test_Services(服务表) 和Test_Visit(回访表)

现要随机抽取一段时间内每位员工服务量数据的40%插入到回访表,以进行回访。 求SQL语句

问：SQL 可否实现类For循环的函数？ 还是要用游标~ 望不吝赐教，多谢



执行以下SQL 构建测试数据：

--用户表
CREATE TABLE Test_user 
(
UserID varchar(50) NOT NULL,
UserName varchar(50) NOT NULL,
PRIMARY KEY (UserID)
)
--服务表
CREATE TABLE Test_Services
(
billno INT NOT NULL IDENTITY   (1,1),
UserID VARCHAR(50) NOT NULL,
CreateTM VARCHAR(50),
PRIMARY KEY (billno)
)

-- 回访表
CREATE TABLE Test_Visit
(
billno INT NOT NULL IDENTITY   (1,1),
UserID VARCHAR(50) NOT NULL,
CreateTM VARCHAR(50),
PRIMARY KEY (billno)
)

-- 插入回访数据
INSERT INTO Test_user (UserID,UserName) VALUES('XiaoE','小二')
INSERT INTO Test_user (UserID,UserName) VALUES('ZhangS','张三')
INSERT INTO Test_user (UserID,UserName) VALUES('Lis','李四')


INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-21 16:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-22 16:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-23 16:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-24 16:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-25 16:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-26 16:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-27 16:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-21 16:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-22 15:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-23 15:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-24 15:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-25 15:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('XiaoE','2012-03-26 15:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-21 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-21 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-21 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-21 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-23 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-22 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-23 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-22 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-24 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-24 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-24 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('ZhangS','2012-03-24 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('Lis','2012-03-24 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('Lis','2012-03-24 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('Lis','2012-03-24 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('Lis','2012-03-24 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('Lis','2012-03-25 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('Lis','2012-03-26 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('Lis','2012-03-27 10:04:57')
INSERT INTO Test_Services (UserID,CreateTM) VALUES('Lis','2012-03-28 10:04:57')

[开着拖拉机泡妞]

while可以实现for循环

[阿呆哥]

当然可以。

[快溜]

insert into Test_Visit
 select distinct b.* from Test_user a
cross apply(select top percent 40 * 
      from Test_Services where UserID=a.UserID and
       CreateTM between @bengintime and @endtime order by newid()) b

[Felixzhaowenzhong]

while 条件
begin
SQL语句
继续 while 条件
end