试图写有开始时间和结束时间

林具有这些表分贝的存储过程：试图写有开始时间和结束时间

drop table if exists events1; 
create table if not exists events1(
    time_stamp   decimal(16,6),  
    message    char(90)  not null default 'defult message' 
); 

drop table if exists events2; 
create table if not exists events2(
    time_stamp   decimal(16,6),  
    message    char(90)  not null default 'defult message' 
); 

drop table if exists events3; 
create table if not exists events3(
    time_stamp   decimal(16,6),  
    message    char(90)  not null default 'defult message' 
); 

insert into events1 (time_stamp,message) values (1485193300,"a1"); 
insert into events1 (time_stamp,message) values (1485193600,"b1"); 
insert into events1 (time_stamp,message) values (1485193900,"c1"); 

insert into events2 (time_stamp,message) values (1485193300,"a1"); 
insert into events2 (time_stamp,message) values (1485193600,"b2"); 
insert into events2 (time_stamp,message) values (1485193900,"c3"); 

insert into events3 (time_stamp,message) values (1485193300,"a1"); 
insert into events3 (time_stamp,message) values (1485193600,"b2"); 
insert into events3 (time_stamp,message) values (1485193900,"c3");

我试图建立一个存储过程，有3个参数：

start_time (int) (in epoch) 
end_time (int) (in epoch) 
interval (int) (in epoch)

我不希望这个程序会迭代start_time，步骤为区间直到end_time，并在每次迭代时，根据步骤和时间间隔获得三个表的并集。

类似：

DELIMITER // 
CREATE PROCEDURE get_events 
(IN start_time INT, 
IN end_time INT, 
IN interval INT, 
) 
BEGIN 
     while [ start_time <= end_time] 
      do 
      next_time = start_time + interval 
      select * 
      from events1 
      where start_time <= time_stamp and time_stamp <= next_time 

      union 

      select * 
      from events2 
      where start_time <= time_stamp and time_stamp <= next_time 

      union 

      select * 
      from events3 
      where start_time <= time_stamp and time_stamp <= next_time 

      start_time = start_time + interval 


     end while 

END // 
DELIMITER ;

我知道我有语法错误，我不知道我怎样才能返回结果，并在WHERE情况下给定的时间间隔遍历3代表的联合。

请指教。

来源

2017-01-23 Amit_A

你所说的“返回结果”是什么意思？ 'UNION'将为WHILE每次迭代返回一个结果集。 –

什么是语法错误？

[是无效的语法;或许(在WHILE？

a = a + b是无效的语法;请参阅SET命令。

具有相同模式的3个表格是通常是一个糟糕的设计。

使用CHAR而不是VARCHAR我们通常是一个坏主意。

来源

2017-01-23 18:41:42

我写了架构只是为了说明。我被困在存储过程中。我把它们写成伪代码的时候，我不知道如何保存每个迭代的查询结果，以及如何返回所有结果。 –

INSERT INTO "table name" 
select * 
    from events1 
    where start_time <= time_stamp and time_stamp <= next_time 

    union 

    select * 
    from events2 
    where start_time <= time_stamp and time_stamp <= next_time 

    union 

    select * 
    from events3 
    where start_time <= time_stamp and time_stamp <= next_time

这会将查询存储在一个表中，然后您可以遍历该表。不知道这是你要求的。

下面是文档： https://dev.mysql.com/doc/refman/5.7/en/insert-select.html

来源

2017-01-23 19:03:27

试图写有开始时间和结束时间

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