需求: 给出如下条件进行批处理编排 - 开始日期时间 - 重复间隔(分钟) - 重复次数 要求在档期内重复安排节目播出, 比如: 2003.01.01 08:00 开始每隔240分钟播出一次, 一共播出100次
数据库表格(CO_SCHEDULE) ------------------------------ N_PROGIDINT DT_STARTTIMETIMESTAMP DT_ENDTIMETIMESTAMP
存储过程的实现:
create table co_schedule(n_progid int,dt_starttime timestamp,dt_endtime timestamp);
//创建函数: create function add_program_time(int4,timestamp,int4,int4,int4) returns bool as ' declare prog_id alias for $1; duration_min alias for $3; period_min alias for $4; repeat_times alias for $5; i int; starttime timestamp; ins_starttime timestamp; ins_endtime timestamp; begin starttime :=$2; i := 0; while i<repeat_times loop ins_starttime := starttime; ins_endtime := timestamp_pl_span(ins_starttime,duration_min || ''mins''); starttime := timestamp_pl_span(ins_starttime,period_min || ''mins''); insert into co_schedule values(prog_id,ins_starttime,ins_endtime); i := i+1; end loop; if i<repeat_times then return false; else return true; end if; end; 'language 'plpgsql';
//执行函数: select add_program_time(1,'2002-10-20 0:0:0','5','60','5');
//查看结果:select * from co_schedule; n_progid |dt_starttime| dt_endtime ----------+------------------------+------------------------ 1 | 2002-10-20 00:00:00+08 | 2002-10-20 00:05:00+08 1 | 2002-10-20 01:00:00+08 | 2002-10-20 01:05:00+08 1 | 2002-10-20 02:00:00+08 | 2002-10-20 02:05:00+08 1 | 2002-10-20 03:00:00+08 | 2002-10-20 03:05:00+08 1 | 2002-10-20 04:00:00+08 | 2002-10-20 04:05:00+08
ps: 1.数据库一加载 plpgsql语言。如没有, su - postgres createlang plpgsql dbname 2.至于返回类型为bool,是因为我不知道如何让函数不返回值。等待改进。
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