我有一个递归查询,封装在一个函数中,它返回一个分层调查“结构”:
CREATE OR REPLACE FUNCTION get_survey_results(IN v_survey_id integer DEFAULT 1, IN v_survey_session_id integer DEFAULT NULL)
RETURNS TABLE(sort_order bigint[], survey_question_id integer, question_text text, required_ind smallint, survey_session_id integer, custom_text text, option_value integer, survey_scale_id integer, survey_scale_type_id integer, parent_survey_question_id integer, parent_survey_scale_option_id integer) AS
$BODY$
BEGIN
RETURN QUERY
WITH RECURSIVE Survey_Structure (PATH, survey_question_id, question_text,
required_ind, survey_session_id, custom_text,
option_value, survey_scale_id, survey_scale_type_id,
parent_survey_question_id, parent_survey_scale_option_id, CYCLE)
AS (
SELECT ARRAY[row_number() OVER (ORDER BY Survey_Question.sort_order)], Survey_Question.survey_question_id, Survey_Question.question_text,
Survey_Question.required_ind, Survey_Response.survey_session_id, Survey_Response.custom_text,
Survey_Scale_Option.option_value, Survey_Question.survey_scale_id, Survey_Scale.survey_scale_type_id,
0 as parent_survey_question_id, 0 AS parent_survey_scale_option_id, FALSE
FROM ...etc...
我可以将 survey_id 传递给此函数 (SELECT * FROM get_survey_results(1)
),它会返回该调查的所有问题和答案。
我想通过以下方式确定层次结构中节点的“级别”:
SELECT question_text, array_length(sort_order) AS level,
...etc...
FROM get_survey_results(1)
我的查询返回错误
function array_length(bigint[]) does not exist
PostgreSQL array documentation promise arrar_length() 将处理“任何数组”。
我做错了什么?是否有我需要安装的可选包?
最佳答案
仔细检查文档会发现 array_length()
采用两个 参数。
我只需要改变
SELECT question_text, array_length(sort_order) AS level, ...
到
SELECT question_text, array_length(sort_order, 1) AS 级别, ...
关于postgresql - 修复错误 "function array_length(bigint[]) does not exist",我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/21173086/