以下python语句sql = """ SELECT date_z, COUNT(*) + IFNULL(nn, 0) FROM ( SELECT id_person, date_z, date_finish FROM luzhi_jilu_all WHERE id_person = %s AND (date_z = date_finish OR date_finish IS NULL) ) AS t1 LEFT JOIN ( SELECT id_person, date_finish, COUNT(*) AS nn FROM luzhi_jilu_all GROUP BY id_person, date_finish ) AS t2 ON t1.id_person = t2.id_person AND t1.date_z = t2.date_finish GROUP BY date_z ORDER BY date_z DESC """ params = (id_person,) cs.execute(sql, params) jg = cs.fetchall()提示出现以下错误pymysql.err.InternalError: (1055, "Expression #2 of SELECT list is not in GROUP BY clause and contains nonaggregated column 't2.nn' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by"),请检查错误,并修改
时间: 2024-02-14 10:20:52 浏览: 28
这个错误是由于 MySQL 的 sql_mode=only_full_group_by 模式导致的。在这种模式下,如果 SELECT 语句中的列不在 GROUP BY 子句中,那么这些列必须是聚合函数的参数,或者在 SELECT 子句中使用 IFNULL、CASE 等函数来进行处理。因为在 GROUP BY 子句中聚合分组依赖于 SELECT 子句中的列,如果 SELECT 子句中的列没有在 GROUP BY 子句中出现,那么这些列的值在聚合时是不确定的。
对于这段 SQL 语句,错误出现在 SELECT 子句中的第二个列,即 COUNT(*) + IFNULL(nn, 0)。这个列没有在 GROUP BY 子句中出现,也不是聚合函数的参数,因此需要使用一个聚合函数来处理它。你可以把这个列替换为 SUM(COUNT(*) + IFNULL(nn, 0)),这样就可以避免这个错误了。
修改后的 SQL 语句如下:
sql = """
SELECT date_z, SUM(COUNT(*) + IFNULL(nn, 0))
FROM (
SELECT id_person, date_z, date_finish
FROM luzhi_jilu_all
WHERE id_person = %s AND (date_z = date_finish OR date_finish IS NULL)
) AS t1
LEFT JOIN (
SELECT id_person, date_finish, COUNT(*) AS nn
FROM luzhi_jilu_all
GROUP BY id_person, date_finish
) AS t2 ON t1.id_person = t2.id_person AND t1.date_z = t2.date_finish
GROUP BY date_z
ORDER BY date_z DESC
"""
params = (id_person,)
cs.execute(sql, params)
jg = cs.fetchall()