select sys_connect_by_path(t2.ID, '/') as PATH, t1.id from HTD_DEVICETYPE_RELATION t1 inner join HTD_DEVICETYPE_RESOURCE t2 on t1.CHILD_RESOURCE_TYPE_ID = t2.ID start with t1.parent_resource_type_id = 100 and t1.id > 1 connect by nocycle prior t2.id = t1.parent_resource_ty...
sys_connect_by_path函数就是从start with开始的地方开始遍历,并记下其遍历到的节点,start with开始的地方被视为根节点,将遍历到的路径根据函数中的分隔符,组成一个新的字符串。sys_connect_by_path函数用connect by来寻找下一条记录,直到迭代找不到相应记录为止。概念与递归类似,connect by指定递归(连接)条件,如...
PostgreSQL Oracle 兼容性之 - connect by 高级选项 CONNECT_BY_ISLEAF、SYS_CONNECT_BY_PATH、CONNECT_BY_ISCYCLE、LEVEL
insert into tab_connect_by (CHILD, PARENT) values(1, 26); insert into tab_connect_by (CHILD, PARENT) values(12, 26); insert into tab_connect_by (CHILD, PARENT) values(11, 18); insert into tab_connect_by (CHILD, PARENT) values(7, 18); insert into tab_connect_by (CHILD, PARENT)...
问SYS_CONNECT_BY_PATH并以PostgreSQL等效的方式开始/连接ENPostgreSQL从小白到专家，是从入门逐渐能力提升...
create table hierarchical_functions_tb(VARCHAR2_1 VARCHAR2(100),VARCHAR2_2 VARCHAR2(100)); insert into hierarchical_functions_tb(VARCHAR2_1,VARCHAR2_2) values('hierarchical_functions_tb1','hierarchical_functions_tb2'); select sys_connect_by_path(VARCHAR2_1,'/') from hierarchical_functions_tb...
Oracle中START / WITH / CONNECT BY提供分层查询的能力,从START WITH开始遍历记录,递归查询结果集直到拿到所有满足条件的结果。 例如下面测试数据: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 drop table sr_menu; create table sr_menu( id number(10) not null, parent number(10), title varchar2(...
PostgreSQL is a relational database management system developed by PostgreSQL Global Development Group. Connect to on-premise PostgreSQL database to read data from tables.This connector is available in the following products and regions:展开表
Name of host to connect to. If a host name looks like an absolute path name, it specifies Unix-domain communication rather than TCP/IP communication; the value is the name of the directory in which the socket file is stored. (On Unix, an absolute path name begins with a slash. On ...
例如:在 Oracle 中,我曾经严重依赖“CONNECT BY”子句进行分层查询。PostgreSQL不支持“CONNECT BY”。我不得不使用递归公用表表达式(CTE)重写这些查询,这是PostgreSQL处理分层数据的方式。 2.交易行为Oracle和PostgreSQL处理事务的方式不同。在 Oracle 中,DDL 语句被视为自治事务,并立即提交。相比之下,PostgreSQL将DDL...