Oracle中connect by prior .... start with

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一 connect by prior ....start with

?废话少说上测试代码.

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create table test_table_c(id number primary key,description varchar(255),parent_id number);insert into test_table_c(id,description,parent_id) values(1,'cuiyaonan2',null);insert into test_table_c(id,description,parent_id) values(2,'cuiyaonan20',1);insert into test_table_c(id,description,parent_id) values(3,'cuiyaonan200',2);insert into test_table_c(id,description,parent_id) values(4,'cuiyaonan2000',3);insert into test_table_c(id,description,parent_id) values(5,'cuiyaonan2000@',4);insert into test_table_c(id,description,parent_id) values(6,'cuiyaonan2000@1',5);insert into test_table_c(id,description,parent_id) values(7,'cuiyaonan2000@16',6);

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执行语句

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select * from test_table_c connect by prior parent_id  =  id  start with id =7;

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执行语句

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select * from test_table_c connect by parent_id  =  prior id  start with id =1;

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注释 :prior ?表示上一条记录.?prior +字段 表示上一条记录的某个字段.如?

 parent_id  =  prior id 

表示上一条记录的id与本条记录的parent_id值是否一致.

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