我正在处理的存储过程有时会出错。对于特定的JOB_ID_INPUT值,我会收到“结果由多行组成”的错误。我理解这个错误的原因,并且尽可能小心地确保我的返回值在应该是标量时是标量。由于错误是有条件地抛出的,所以让我认为可能存在内存问题或游标重用。我不经常使用游标,所以我不确定错误可能在哪里产生。感谢任何帮助我的人。
DROP PROCEDURE IF EXISTS export_job_candidates;
DELIMITER $$
CREATE PROCEDURE export_job_candidates (IN JOB_ID_INPUT INT(11))
BEGIN
DECLARE candidate_count INT(11) DEFAULT 0;
DECLARE candidate_id INT(11) DEFAULT 0;
# these are the ib variables
DECLARE _overall_score DECIMAL(5, 2) DEFAULT 0.0;
# declare the cursor that will be needed for this SP
DECLARE curs CURSOR FOR SELECT user_id FROM job_application WHERE job_id = JOB_ID_INPUT;
# this table stores all of the data that will be returned from the various tables that will be joined together to build the final export
CREATE TEMPORARY TABLE IF NOT EXISTS candidate_stats_temp_table (
overall_score_ib DECIMAL(5, 2) DEFAULT 0.0
) engine = memory;
SELECT COUNT(job_application.id) INTO candidate_count FROM job_application WHERE job_id = JOB_ID_INPUT;
OPEN curs;
# loop controlling the insert of data into the temp table that is retuned by this function
insert_loop: LOOP
# end the loop if there is no more computation that needs to be done
IF candidate_count = 0 THEN
LEAVE insert_loop;
END IF;
FETCH curs INTO candidate_id;
# get the ib data that may exist for this user
SELECT
tests.overall_score
INTO
_overall_score
FROM
tests
WHERE
user_id = candidate_id;
#build the insert for the table that is being constructed via this loop
INSERT INTO candidate_stats_temp_table (
overall_score
) VALUES (
_overall_score
);
SET candidate_count = candidate_count - 1;
END LOOP;
CLOSE curs;
SELECT * FROM candidate_stats_temp_table WHERE 1;
END $$
DELIMITER ;