php - 当值超过特定字符数时存储过程抛出错误

Question

BEGIN

SET @sql = NULL;
SELECT
GROUP_CONCAT(DISTINCT
CONCAT(
'MAX(IF(questions= ''',
questions,
''', yes_no, NULL)) AS ''',
questions,''''
)
) INTO @sql
FROM tbl_main where task=in_task;
SET @sql = CONCAT('SELECT case_id,audited_by,resolved_by, ', @sql, ' FROM  tbl_main WHERE task IN  (''',in_task,''') and audited_date   between(''',from_date,''') and (''',to_date,''') GROUP BY   case_id,audited_by,resolved_by');

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;


END

您好，我正在使用存储过程并将行值动态转换为列标题，如果行值在 50 个字左右，存储过程就可以正常工作，而当行值超过 50 个时，存储过程就会失败字 。我不知道如何解决它。谁能帮我解决这个问题。

Answer 1

设置 session group_concat_max_len = 5000;