oracle 中的chain job

--演示环境
scott@CNMMBO> select * from v$version where rownum<2;
 
BANNER
----------------------------------------------------------------
Oracle Database 10g Release 10.2.0.3.0 - 64bit Production
 
--创建演示表及序列
CREATE TABLE tb_schduler
(
   id        NUMBER (10) NOT NULL,
   descr     VARCHAR2 (20) NOT NULL,
   cr_date   DATE NOT NULL,
   CONSTRAINT tb_schduler_pk PRIMARY KEY (id)
);
 
CREATE SEQUENCE tb_schduler_seq;
 
1、创建程序
--下面定义了3个需要用到的程序program，注意这里的program不等同于procedure或者package，但是可以调用procedure或package
--下面的program主要是用于插入记录到测试表
BEGIN
  DBMS_SCHEDULER.create_program (
    program_name   => ‘test_proc_1‘,
    program_type   => ‘PLSQL_BLOCK‘,  -->这里的类型定义为PLSQL_BLOCK，支持STORED PROCEDURE/EXECUTEABLE
    program_action => ‘BEGIN
                         INSERT INTO tb_schduler (id, descr, cr_date)
                         VALUES (tb_schduler_seq.NEXTVAL, ‘‘test_proc_1‘‘, SYSDATE);
                         COMMIT;
                       END;‘,
    enabled        => TRUE,
    comments       => ‘Program for first link in the chain.‘);
 
  DBMS_SCHEDULER.create_program (
    program_name   => ‘test_proc_2‘,
    program_type   => ‘PLSQL_BLOCK‘,
    program_action => ‘BEGIN
                         INSERT INTO tb_schduler (id, descr, cr_date)
                         VALUES (tb_schduler_seq.NEXTVAL, ‘‘test_proc_2‘‘, SYSDATE);
                         COMMIT;
                       END;‘,
    enabled        => TRUE,
    comments       => ‘Program for second link in the chain.‘);
 
  DBMS_SCHEDULER.create_program (
    program_name   => ‘test_proc_3‘,
    program_type   => ‘PLSQL_BLOCK‘,
    program_action => ‘BEGIN
                         INSERT INTO tb_schduler (id, descr, cr_date)
                         VALUES (tb_schduler_seq.NEXTVAL, ‘‘test_proc_3‘‘, SYSDATE);
                         COMMIT;
                       END;‘,
    enabled        => TRUE,
    comments       => ‘Program for last link in the chain.‘);
END;
/
 
2、创建chain
--创建chain比较简单，通常只需要定义一个chain名字即可，主要是用于关联后续定义rule及step
BEGIN
  DBMS_SCHEDULER.create_chain (
    chain_name          => ‘test_chain_1‘,   -->定义chain的名字
    rule_set_name       => NULL,             -->可以指定规则集的名字
    evaluation_interval => NULL,
    comments            => ‘A test chain.‘);
END;
/
 
3、定义chain步骤
--下面定义chain的每一个步骤以及其对应的program_name，也就是每一步需要做什么
BEGIN
  DBMS_SCHEDULER.define_chain_step (
    chain_name   => ‘test_chain_1‘,   --->chain的名字
    step_name    => ‘chain_step_1‘,   --->步骤地名字
    program_name => ‘test_proc_1‘);   --->当前步骤应执行的相应程序
 
  DBMS_SCHEDULER.define_chain_step (
    chain_name   => ‘test_chain_1‘,
    step_name    => ‘chain_step_2‘,
    program_name => ‘test_proc_2‘);
 
  DBMS_SCHEDULER.define_chain_step (
    chain_name   => ‘test_chain_1‘,
    step_name    => ‘chain_step_3‘,
    program_name => ‘test_proc_3‘);
END;
/
 
4、定义chain规则
--用于定义chain根据执行结果应该如何跳转的问题，每个CHAIN 规则都拥有condition和action 属性，
--当满足condition 时则执行action中指定的step。使用DBMS_SCHEDULER.DEFINE_CHAIN_RULE 过程
BEGIN
  DBMS_SCHEDULER.define_chain_rule (
    chain_name => ‘test_chain_1‘,
    condition  => ‘TRUE‘,
    action     => ‘START "CHAIN_STEP_1"‘,
    rule_name  => ‘chain_rule_1‘,
    comments   => ‘First link in the chain.‘);
 
  DBMS_SCHEDULER.define_chain_rule (
    chain_name => ‘test_chain_1‘,
    condition  => ‘"CHAIN_STEP_1" COMPLETED‘,
    action     => ‘START "CHAIN_STEP_2"‘,
    rule_name  => ‘chain_rule_2‘,
    comments   => ‘Second link in the chain.‘);
 
  DBMS_SCHEDULER.define_chain_rule (
    chain_name => ‘test_chain_1‘,
    condition  => ‘"CHAIN_STEP_2" COMPLETED‘,
    action     => ‘START "CHAIN_STEP_3"‘,
    rule_name  => ‘chain_rule_3‘,
    comments   => ‘Third link in the chain.‘);
 
  DBMS_SCHEDULER.define_chain_rule (
    chain_name => ‘test_chain_1‘,
    condition  => ‘"CHAIN_STEP_3" COMPLETED‘,
    action     => ‘END‘,
    rule_name  => ‘chain_rule_4‘,
    comments   => ‘End of the chain.‘);
END;
/
 
5、激活chain
BEGIN
  DBMS_SCHEDULER.enable (‘test_chain_1‘);
END;
/
 
6、将chain添加到job
BEGIN
  DBMS_SCHEDULER.CREATE_JOB (
    job_name        => ‘test_chain_1_job‘,
    job_type        => ‘CHAIN‘,
    job_action      => ‘test_chain_1‘,
    repeat_interval => ‘freq=minutely; interval=2‘,
    start_date      => SYSTIMESTAMP,
    end_date        => SYSTIMESTAMP + (1/48),
    enabled         => FALSE);   --->值为TRUE用于激活JOB 
END;
/
 
7、手动执行chain
BEGIN
  DBMS_SCHEDULER.run_chain (
    chain_name    =>  ‘test_chain_1‘,
    job_name      =>  ‘test_chain_1_run_job‘,
    start_steps   =>  ‘chain_step_1,chain_step_3‘);  -->可以指定单步或多步以及所有步骤
END;
/
 
scott@CNMMBO> select * from tb_schduler;
 
        ID DESCR                CR_DATE
---------- -------------------- -----------------
         1 test_proc_1          20131203 14:36:03
         2 test_proc_3          20131203 14:36:04
 
--激活job   
scott@CNMMBO> exec dbms_scheduler.enable(‘test_chain_1_job‘);
 
PL/SQL procedure successfully completed.