DBMS_SCHEDULER CHAIN用法

--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
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
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
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
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',

--可以改成条件为1、2都完成（CHAIN_STEP_1 COMPLETED AND CHAIN_STEP_2 COMPLETED），同时将规则2的条件改成TRUE

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;

select * from tb_schduler;
--激活job
exec dbms_scheduler.enable('test_chain_1_job');

--三、CHAIN相关状态及视图查询
job_chains --->数据字典dba_scheduler_chains
job_chain_steps --->数据字典dba_scheduler_chain_steps
job_chain_rules --->数据字典 dba_scheduler_chain_rules
job_log_detail --->数据字典dba_scheduler_job_run_details
select * from tb_schduler;

--四、移除CHAIN及相关JOB
对于与chain相关的program，rule，由于存在依赖性，因此需要先删除job，然后可以删除chain，program等
EXEC DBMS_SCHEDULER.drop_job(job_name => 'test_chain_1_job');
EXEC DBMS_SCHEDULER.drop_chain (chain_name => 'test_chain_1');
EXEC DBMS_SCHEDULER.drop_program (program_name => 'test_proc_1');
EXEC DBMS_SCHEDULER.drop_program (program_name => 'test_proc_2');
EXEC DBMS_SCHEDULER.drop_program (program_name => 'test_proc_3');

--注：rule的条件有些复杂，网上搜索了一点应该够用了：

其语法看起来稍稍复杂一些，或者说是灵活，condition参数值支持下列的语法形式：
TRUE
FALSE
stepname[NOT]SUCCEEDED
stepname[NOT]FAILED
stepname[NOT]STOPPED
stepname[NOT]COMPLETED
stepname ERROR_CODE IN(integer,integer,integer...)
stepname ERROR_CODE NOT IN(integer,integer,integer...)
stepname ERROR_CODE=integer
stepname ERROR_CODE!=integer
stepname ERROR_CODE<>integer
stepname ERROR_CODE>integer
stepname ERROR_CODE>=integer
stepname ERROR_CODE<integer
stepname ERROR_CODE<=integer
甚至于，还可以制定成下列逻辑语法:
expression AND expression
expression OR expression
NOT(expression)