使用jdbc访问PostgreSQL或者MogDB(openGauss)数据库里的cursor游标时，官方文档可查的资料较少，下面的示例供参考。

测试环境

• JDBC：postgresql-42.3.5.jar
• PG: 14.2
• MogDB(openGauss): 3.0.0

测试背景

针对function和procedure返回cursor游标类型，通过jdbc如何调用。

测试function：curtest1，通过returns返回游标类型

create or replace function curtest1() 
returns refcursor 
language plpgsql
as $function$ 
declare 
    cur refcursor;
begin 
    open cur for select id,data from fiverows;
    return cur;
end;
$function$;

测试procedure：curtest2，通过out参数返回游标类型

create or replace procedure curtest2(out cur refcursor) 
language plpgsql
as $procedure$ 
begin 
    open cur for select id,data from fiverows;
end;
$procedure$;

测试procedure：curtest3，通过out参数返回多个游标类型

create or replace procedure curtest3(out cur1 refcursor,out cur2 refcursor) 
language plpgsql
as $procedure$ 
begin 
    open cur1 for select id,data from fiverows where id between 1 and 3;
    open cur2 for select id,data from fiverows where id between 4 and 5;
end;
$procedure$;

表结构及数据

create table fiverows(id serial primary key,data text);
insert into fiverows(data) values('one'),('two'),
                       ('three'),('four'),('five');

测试一：function通过returns返回游标