Sql server 我需要连接两个表以从student_info表中获取所有记录

我需要连接两个表，以获取来自student_info表的所有记录，以及来自student_activities表的记录，其中student_id相等

由于单个学生id的学生活动表中可能有多条记录，因此当我使用左联接打印输出时，会得到重复的记录

SELECT *
FROM student_info 
LEFT JOIN student_activities 
ON student_info.student_id=student_activities.student _id

有人建议我使用以下内容，但我得到的错误是，特定字段不是聚合函数的一部分

SELECT student_info.student_id, student_info.student_name, student_info.phone, student_info.age, COUNT (student_activities.student_id) AS COA
FROM student_info 
LEFT OUTER JOIN student_activities 
ON student_info.student_id=student_activities.student_id 
GROUP BY student_info.student_id

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未经测试，但应能正常工作或类似以下情况：

SELECT DISTINCT *
FROM student_info 
WHERE student_info.student_id = 
(SELECT student_activities.student _id FROM student_activities)

SELECT DISTINCT *
FROM student_info 
WHERE student_info.student_id = 
(SELECT student_activities.student _id FROM student_activities)

SELECT 
 student_info.student_id, 
 student_info.student_name, 
 student_info.phone, 
 student_info.age, 
 COUNT (student_activities.student_id) AS COA
FROM student_info LEFT OUTER JOIN student_activities 
ON student_info.student_id=student_activities.student_id 
GROUP BY student_info.student_id,student_info.student_name, student_info.phone, student_info.age