postgresql - PostgreSql 12 JDBC 多结果集，只能获取第一个结果集

Question

希望 JDBC 从 PostgreSql 12 函数中获取多个结果集。JDBC 版本 org.postgresql/postgresql/42.2.9。PostgreSql 函数在这里：

create or replace function test()
returns setof refcursor as $$
declare
    ret1 refcursor;
    ret2 refcursor;
begin
    open ret1 for
    select 10 as a;
    return next ret1;
    open ret2 for
    select 20 as b;
    return next ret2;
end; $$ language plpgsql;

Java代码是这样的：

stmt = getConnection().prepareCall("{ ? = call test() }");
stmt.registerOutParameter(1, Types.OTHER);
stmt.execute();
rs = (ResultSet)stmt.getObject(1);
if (rs.next()) {
    int a = rs.getInt("a");
    if (rs.next()) {
        int b = rs.getInt("b");
    }
}

“a”被成功检索，但第二个“rs.next()”返回 false。谷歌搜索了很多，但无法使其工作。如何获得第二个结果集？

Answer 1

这个链接对我帮助很大，问题得到了解决。

    ...
    out ret1 refcursor,
    out ret2 refcursor)
returns record as $$
begin
    open ret1 for select 10;
    open ret2 for select 20;
end; $$ language plpgsql;

爪哇：

stmt = getConnection().prepareCall("{call test(?,?)}");
stmt.registerOutParameter(1, Types.OTHER);
stmt.registerOutParameter(2, Types.OTHER);
stmt.execute();
ResultSet rs1 = (ResultSet)stmt.getObject(1);
ResultSet rs2 = (ResultSet)stmt.getObject(2);
int a = 0, b = 0;
if (rs1.next()) {
    a = rs1.getInt(1);
}
if (rs2.next()) {
    b = rs2.getInt(1);
}