CREATE OR REPLACE FUNCTION getParentLtree(parent_id bigint, tbl_name varchar)
RETURNS ltree AS
$BODY$
DECLARE
parent_ltree ltree;
BEGIN
-- This works fine:
-- select into parent_ltree l_tree from tbl1 where id = parent_id;
EXECUTE format('select into parent_ltree l_tree from %I
where id = %I', tbl_name,parent_id);
RETURN parent_ltree;
END;
$BODY$ LANGUAGE plpgsql;
以上函数存在2个问题:
parent_id
是integer
类型,但被引号替代了?int
变量的正确格式说明符是什么?select into
不能与EXECUTE
一起使用?如何使上述被注释的查询使用传递的表名?